SANS Software Security Institute
SANS Software Security Institute
Home > Resources > Top-20

SANS Top-20 Internet Security Attack Targets (2006 Annual Update)

Operating Systems
W1. Internet Explorer
W2. Windows Libraries
W3. Microsoft Office
W4. Windows Services
W5. Windows Configuration Weaknesses
M1. Mac OS X
U1. UNIX Configuration Weaknesses
Cross-Platform Applications
C1 Web Applications
C2. Database Software
C3. P2P File Sharing Applications
C4 Instant Messaging
C5. Media Players
C6. DNS Servers
C7. Backup Software
C8. Security, Enterprise, and Directory Management Servers
Network Devices
N1. VoIP Servers and Phones
N2. Network and Other Devices Common Configuration Weaknesses
Security Policy and Personnel
H1. Excessive User Rights and Unauthorized Devices
H2. Users (Phishing/Spear Phishing)
Special Section
Z1. Zero Day Attacks and Prevention Strategies
Introduction

Six years ago, the SANS Institute and the National Infrastructure Protection Center (NIPC) at the FBI released a document summarizing the Ten Most Critical Internet Security Vulnerabilities. Thousands of organizations relied on that list, and on the expanded Top-20 lists that followed in succeeding years, to prioritize their efforts so they could close the most dangerous holes first. The vulnerable services that led to worms like Blaster, Slammer, and Code Red have been on SANS Top20 lists.

The SANS Top-20 2006 list is not "cumulative." We have listed only critical vulnerabilities from the past year or so. If you have not patched your systems for a length of time, it is highly recommended that you patch the vulnerabilities listed in the Top-20 2005 list as well as those in the 2006 list. At the end of this document, you will find a short SANS Top-20 FAQ (frequently asked questions) that answers questions you may have about the project and the way the list is created.

The SANS Top-20 2006 is a consensus list of vulnerabilities that require immediate remediation. It is the result of a process that brought together dozens of leading security experts. They come from the most security-conscious government agencies in the UK, US, and Singapore; the leading security software vendors and consulting firms; the top university-based security programs; the Internet Storm Center, and many other user organizations. A list of participants is at the end of this document.

The SANS Top-20 is a living document. It includes step-by-step instructions and pointers to additional information useful for correcting the security flaws. We will update the list and the instructions as more critical threats and more current or convenient methods of protection are identified, and we welcome your input along the way. This is a community consensus document -- your experience in fighting attackers and in eliminating the vulnerabilities can help others who come after you. Please send suggestions via e-mail to top20@sans.org

Version 7.0 November 15, 2006
Copyright © 2006, SANS Institute
Questions / comments may be directed to top20@sans.org.
To link to the Top 20 List, use the "SANS Top 20 List" logo

PDF | Printer Friendly Version

W1. Internet Explorer

W1.1 Description

Microsoft Internet Explorer is the most popular browser used for web surfing and is installed by default on each Windows system. Unpatched or older versions of Internet Explorer contain multiple vulnerabilities that can lead to memory corruption, spoofing and execution of arbitrary scripts. The most critical issues are the ones that lead to remote code execution without any user interaction when a user visits a malicious webpage or reads an email. Exploit code for many of the critical Internet Explorer flaws are publicly available. In addition, Internet Explorer has been leveraged to exploit vulnerabilities in other core Windows components such as HTML Help and Graphics Rendering Engine. Vulnerabilities in ActiveX controls installed by Microsoft or other vendor software are also being exploited via Internet Explorer.

These flaws have been widely exploited to install spyware, adware and other malware on users' systems. The spoofing flaws have been leveraged to conduct phishing attacks. In many cases, the vulnerabilities were zero-days i.e. no patch was available at the time the vulnerabilities were publicly disclosed. The VML zero-day vulnerability fixed by Microsoft patch MS06-055 was widely exploited by malicious websites before the patch was available.

During the past year Microsoft has released multiple updates for Internet Explorer.

  • Vulnerability in Vector Markup Language Could Allow Remote Code Execution (MS06-055)
  • Cumulative Security Update for Internet Explorer (MS06-042)
  • Vulnerability in Microsoft JScript Could Allow Remote Code Execution (MS06-023)
  • Cumulative Security Update for Internet Explorer (MS06-021)
  • Cumulative Security Update for Internet Explorer (MS06-013)
  • Cumulative Security Update for Internet Explorer (MS06-004)
  • Cumulative Security Update for Internet Explorer (MS05-054)

Note that the latest cumulative update for Internet Explorer includes all the previous cumulative updates.

Although MS06-051 is a patch for Windows kernel, it is important for Internet Explorer; without this patch, a denial-of-service vulnerability in Internet Explorer can be reliably exploited to execute arbitrary code.

W1.2 Operating Systems Affected

Internet Explorer 5.x and 6.x running on Windows 98/ME/SE, Windows NT Workstation and Server, Windows 2000 Workstation and Server, Windows XP Home and Professional, and Windows 2003 are all potentially vulnerable.

W1.3 CVE Entries

CVE-2005-2831, CVE-2006-0020, CVE-2006-1185, CVE-2006-1186, CVE-2006-1188, CVE-2006-1189, CVE-2006-1245, CVE-2006-1303, CVE-2006-1313, CVE-2006-1359, CVE-2006-1388, CVE-2006-2218, CVE-2006-2382, CVE-2006-2383, CVE-2006-3450, CVE-2006-3451, CVE-2006-3637, CVE-2006-3638, CVE-2006-3639, CVE-2006-3873, CVE-2006-4868

W1.4 How to Determine If You Are at Risk

Use any vulnerability scanner to check whether your systems are patched against these vulnerabilities. You can also consider using the Microsoft Windows Server Update Services (WSUS), Microsoft Baseline Security Analyzer (MBSA), Windows Live Scanner or Systems Management Server (SMS) to check the security patch status of your systems.

W1.5 How to Protect against These Vulnerabilities

  • If you are using Internet Explorer on your system, the best way to remain secure is to upgrade to Windows XP Service Pack 2. The improved operating system security and Windows Firewall will help mitigate risk. For those unable to use Windows XP with Service Pack 2, it is strongly recommended that another browser be used.

  • It is also recommended to upgrade to version 7 of Internet Explorer, which provides improved security over previous versions. The latest version of Internet Explorer, IE7, is being distributed by Microsoft as a Critical Update (KB926874)

  • Keep the systems updated with all the latest patches and service packs. If possible enable Automatic Updates on all systems.

  • Watching out for Microsoft Security Advisories and implementing suggested mitigations before the patch becomes available could alleviate exposure to zero day attacks.

  • To prevent exploitation of remote code execution vulnerabilities at Administrator level, tools like Microsoft DropMyRights can be used to implement "least privileges" for Internet Explorer.

  • Prevent vulnerable ActiveX components from running inside Internet Explorer via the "killbit" mechanism.

  • Many spyware programs are installed as Browser Helper Objects. A Browser Helper Object or BHO is a small program that runs automatically every time Internet Explorer starts and extends its functionalities. Browser Helper Objects can be detected with Antispyware scanners.

  • Use Intrusion Prevention/Detection Systems, Anti-virus, Anti-Spyware and Malware Detection Software to block malicious HTML script code.

  • Windows 98/ME/NT are no longer supported for updates. Legacy users should consider upgrading to Windows XP.

  • Consider using other browsers such as Mozilla Firefox that do not support ActiveX technology.

W1.6 How to Secure Internet Explorer

To configure the Security settings for Internet Explorer:

  • Select Internet Options under the Tools menu.

  • Select the Security tab and then click Custom Level for the Internet zone.

  • Most of the flaws in IE are exploited through Active Scripting or ActiveX Controls.

  • Under Scripting, select Disable for Allow paste operations via script to prevent content from being exposed from your clipboard. Note: Disabling Active Scripting may cause some web sites not to work properly. ActiveX Controls are not as popular but are potentially more dangerous as they allow greater access to the system.

  • Select Disable for Download signed and unsigned ActiveX Controls. Also select Disable for Initialize and script ActiveX Controls not marked as safe.

  • Java applets typically have more capabilities than scripts. Under Microsoft VM, select High safety for Java permissions in order to properly sandbox the Java applet and prevent privileged access to your system.

  • Under Miscellaneous select Disable for Access to data sources across domains to avoid Cross-site scripting attacks.

  • Ensure that no un-trusted sites are in the Trusted sites or Local intranet zones as these zones have weaker security settings than the other zones.

W1.7 References

Internet Explorer Security Updates

US-CERT Securing Web Browser Information

top^

W2. Windows Libraries

W2.1 Description

Windows libraries are modules that contain functions and data that can be used by other modules such as Windows applications. Windows applications typically leverage a large number of these libraries often packaged as dynamic-link library (DLL) files to carry out their functions. These libraries usually have the file extension DLL or OCX (for libraries containing ActiveX controls).

DLLs provide a way to modularize applications so that their functionality can be updated and reused easily. DLLs also help to reduce memory overhead when several applications use the same functionality at the same time. These libraries are used for many common tasks such as HTML parsing, image format decoding and protocol decoding. Local as well as remotely accessible applications use these libraries. Thus, a critical vulnerability in a library usually impacts a range of applications from Microsoft and third-party vendors that rely on that library. Often the exploitation is possible via multiple attack vectors. For instance, the flaws in image processing libraries can be exploited via Internet Explorer, Office and image viewers. In most cases, the libraries are used by all flavors of Windows operating systems, which increase the number of systems available for attacks.

During the past year, several windows libraries were reported to have critical vulnerabilities. In a number of cases, exploit codes were discovered before patches were available (zero-day).

In December 2005, a vulnerability (CVE-2005-4560) was reported in the Graphics Rendering Engine: when handling specially crafted Windows Metafile (WMF) images, it could cause arbitrary code to be executed. Several malicious exploits and malwares were discovered spreading widely over the Internet soon after the discovery. As this vulnerability can be exploited by simply viewing a malicious WMF image file (through websites or attachments), many applications were reported to be affected. Even some of the Lotus Notes versions were reported to be affected by this WMF zero-day exploit. A patch was not available until early January 2006. Details of this vulnerability and exploits can be found at: http://isc.sans.org/diary.php?storyid=993.

As vulnerabilities in Windows libraries can be exploited in multiple vectors, in many cases a remote attacker will just need to persuade a user to access a specially crafted website, image, icon, or cursor file and the attacker would be able to execute arbitrary code on that user's system, with their privileges.

The critical libraries affected during past year include:

  • Vulnerability in Windows Explorer Could Allow Remote Execution (MS06-057, MS06-015).
  • Vulnerabilities in Microsoft Windows Hyperlink Object Library Could Allow Remote Code Execution (MS06-050)
  • Vulnerability in HTML Help Could Allow Remote Code Execution (MS06-046)
  • Vulnerability in Microsoft Windows Could Allow Remote Code Execution (MS06-043)
  • Vulnerability in Graphics Rendering Engine Could Allow Remote Code Execution (MS06-026, MS06-001)
  • Vulnerability in Embedded Web Fonts Could Allow Remote Code Execution (MS06-002)

W2.2. Operating Systems Affected

Windows NT, Windows 2000, Windows XP, Windows 2003

W2.3. CVE Entries

CVE-2005-4560, CVE-2006-0010, CVE-2006-0012, CVE-2006-2376, CVE-2006-2766, CVE-2006-3086, CVE-2006-3357, CVE-2006-3438, CVE-2006-3730, CVE-2006-4868

W2.4. How to Determine If You Are at Risk

  • Use any vulnerability scanner to check whether your systems are patched against these vulnerabilities. You can also consider using the Microsoft Windows Server Update Services (WSUS), Microsoft Baseline Security Analyzer (MBSA), Windows Live Scanner or Systems Management Server (SMS) to check the security patch status of your systems.

  • You can also verify the presence of a patch by checking the registry key mentioned in the Registry Key Verification section of the corresponding security advisory. Additionally, it is advisable to also make sure the updated file versions mentioned in the advisory are installed on the system.

W2.5. How to Protect against These Vulnerabilities

  • Ensure that your Windows systems have all the latest security patches installed.

  • Block the ports 135-139/tcp, 445/tcp and other ports used by Windows systems at the network perimeter. This prevents a remote attacker from exploiting the vulnerabilities via shared file systems.

  • Use TCP/IP Filtering available in Windows 2000 and XP, Windows Firewall in Windows XP systems or any third party personal firewall to block inbound access to the affected ports. It is important that the firewall is properly configured to block against external attacks effectively.

  • Intrusion Prevention/Detection Systems as well as anti-virus and malware detection software are very helpful in providing additional protection from malware and exploits that are exploiting these vulnerabilities.

  • If you are running third-party applications on customized Windows 2000/XP platforms, ensure that an appropriate patch from the vendor has been applied.

  • Follow the principle of "Least Privilege" to limit worms and Trojans from getting a foothold on any systems. Further details about limiting access to certain registry keys, executables and directories are available in the NSA guides at http://www.nsa.gov/snac/index.cfm?MenuID=scg10.3.1.

  • Use system hardening guidelines (such as those from CISecurity ) to make systems more resistant to remote and local attacks.

  • Keep up-to-date on Microsoft security news and patches (http://www.microsoft.com/security/default.mspx ).

  • Due to the large number of attack vectors, be vigilant when receiving email attachment from unsolicited emails and surfing to unknown websites. Do not click on unsolicited links received in emails, instant messages, web forums, or internet relay chat (IRC) channels.

  • Windows NT is no longer supported. Users should upgrade to Windows XP/2003.

W2.6. References

Vulnerability in Windows Explorer Could Allow Remote Execution
http://www.microsoft.com/technet/security/Bulletin/MS06-057.mspx
http://www.microsoft.com/technet/security/Bulletin/MS06-015.mspx

Vulnerability in Vector Markup Language Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/Bulletin/MS06-055.mspx

Vulnerabilities in Microsoft Windows Hyperlink Object Library Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/bulletin/MS06-050.mspx
http://www.microsoft.com/technet/security/bulletin/MS05-015.mspx

Vulnerability in HTML Help Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/Bulletin/MS06-046.mspx
http://www.microsoft.com/technet/security/bulletin/MS05-026.asp
http://www.microsoft.com/technet/security/bulletin/MS05-001.asp

Vulnerability in Microsoft Windows Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/bulletin/MS06-043.asp

Vulnerability in Graphics Rendering Engine Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/bulletin/MS06-026.asp
http://www.microsoft.com/technet/security/bulletin/MS06-001.asp
http://www.microsoft.com/technet/security/bulletin/MS05-053.asp

Vulnerability in Embedded Web Fonts Could Allow Remote Code Execution
http://www.microsoft.com/technet/security/bulletin/MS06-002.asp

top^

W3. Microsoft Office

W3.1 Description

Microsoft Office is the most widely used email and productivity suite worldwide. The applications include Outlook, Word, PowerPoint, Excel, Visio, FrontPage and Access. Vulnerabilities in these products can be exploited via the following attack vectors:

  • The attacker sends the malicious Office document in an email message. Viruses can exploit this attack vector.

  • The attacker hosts the document on a web server or shared folder, and entices a user to browse the webpage or the shared folder. Note that Internet Explorer automatically opens Office documents. Hence, browsing the malicious webpage or folder is sufficient for the vulnerability exploitation.

  • The attacker runs a news server or hijacks a RSS feed that sends malicious documents to email clients.

A large number critical flaws were reported last year in MS Office applications. Moreover, a few of them (CVE-2006-5296, CVE-2006-4694, CVE-2006-4534, CVE-2006-3649, CVE-2006-3590, CVE-2006-3059, CVE-2006-2492, CVE-2006-1540, CVE-2006-1301) were exploited at a zero-day stage when no fix was available from the vendor, which represents a growing trend. Exploit code and technical details are publicly available for some of these vulnerabilities.

The critical flaws that were reported last year in Office and Outlook Express are:

  • PowerPoint Remote Code Execution Vulnerability (CVE-2006-5296)
  • Word Malformed Stack Vulnerability (MS06-060)
  • Office and PowerPoint Mso.dll Vulnerability (MS06-062, MS06-048)
  • Excel Multiple Remote Code Execution Vulnerabilities (MS06-059)
  • PowerPoint Malformed Record Vulnerability (MS06-058)
  • Visio, Works and Projects VBA Vulnerability (MS06-047)
  • Office Malformed String Parsing Vulnerability (MS06-038)
  • Excel Malformed SELECTION record Vulnerability (MS06-037)
  • Word Malformed Object Pointer Vulnerability (MS06-027)
  • Outlook and Exchange TNEF Decoding Remote Code Execution (MS06-003)

W3.2 Operating Systems Affected

Windows 9x, Windows 2000, Windows XP, Windows 2003 are all vulnerable depending on the version of Office software installed.

W3.3 CVE Entries

CVE-2006-5296, CVE-2006-4694, CVE-2006-4534, CVE-2006-3649, CVE-2006-3590, CVE-2006-3059, CVE-2006-2492, CVE-2006-1540, CVE-2006-1301, CVE-2006-0002

W3.4 How to Determine If You Are at Risk

The MS Office installations running without the patches referenced in the Microsoft Bulletins listed from the NVD entries are vulnerable. Use any vulnerability scanner to check whether your systems are patched against these vulnerabilities. You can also consider using the Microsoft Windows Server Update Services (WSUS), Microsoft Baseline Security Analyzer (MBSA), Windows Live Scanner or Systems Management Server (SMS) to check the security patch status of your systems.

W3.5 How to Protect against the Microsoft Office Vulnerabilities

  • Keep the systems updated with all the latest patches and service packs. If possible enable Automatic Updates on all systems.

  • Disable Internet Explorer feature of automatically opening Office documents.

  • Configure Outlook and Outlook Express with enhanced security.

  • Use Intrusion Prevention/Detection Systems and Anti-virus and Malware Detection Software to prevent malicious server responses and documents from reaching the end users.

  • Use mail and web filtering systems at the network perimeter to prevent malicious Office documents from reaching end-user systems.

W3.6 References

Microsoft Office zero-day Discussions
http://blogs.technet.com/msrc/archive/2006/10/12/poc-published-for-ms-office-2003-powerpoint.aspx
http://blogs.securiteam.com/?p=508
http://www.symantec.com/enterprise/security_response/writeup.jsp?docid=2006-081616-2104-99
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=TROJ%5FMDROPPER%2EBI&VSect=T
http://blogs.securiteam.com/?p=451
http://www.symantec.com/security_response/writeup.jsp?docid=2006-051911-0706-99
http://www.symantec.com/security_response/writeup.jsp?docid=2006-051914-5151-99

top^

W4. Windows Services

W4.1 Description

The family of Windows Operating systems supports a wide variety of services, networking methods and technologies. Many of these components are implemented as Service Control Programs (SCP) under the control of Service Control Manager (SCM), which runs as Services.exe. Vulnerabilities in these services that implement these Operating System functions are one of the most common avenues for exploitation.

Several of the core system services provide remote interfaces to client components through Remote Procedure Calls (RPC). They are mostly exposed through named pipe endpoints accessible through the Common Internet File System (CIFS) protocol, well known TCP/UDP ports and in certain cases ephemeral TCP/UDP ports. Historically, there have been many vulnerabilities in services that can be exploited by anonymous users. When exploited, these vulnerabilities afford the attacker the same privileges that the service had on the host.

Earlier versions of the operating system, especially Windows NT and Windows 2000, enabled many of these services by default for a better out of the box experience. These non essential services increase the exploit surface significantly.

The critical vulnerabilities were reported in the following Windows Services within the past year:

Exploit code is available for these vulnerabilities. For instance, the vulnerability addressed by hotfix MS06-040 was exploited by the worms W32.Dasher.G and W32.Spybot.AKNO.

W4.2 Operating Systems Affected

Windows 2000 Workstation and Server, Windows XP Home and Professional, and Windows 2003 are all potentially vulnerable.

W4.3 CVE Entries

CVE-2006-0027, CVE-2006-1314, CVE-2006-2370, CVE-2006-2371, CVE-2006-3439

W4.4 How to Determine If You Are at Risk

  • Use any vulnerability scanner to check whether your systems are patched against these vulnerabilities. You can also consider using the Microsoft Windows Server Update Services (WSUS), Microsoft Baseline Security Analyzer (MBSA), Windows Live Scanner or Systems Management Server (SMS) to check the security patch status of your systems.

  • You can also verify the presence of a patch by checking the registry key mentioned in the Registry Key Verification section of the corresponding security advisory. Additionally, it is advisable to also make sure the updated file versions mentioned in the advisory are installed on the system.

  • To check if your system is vulnerable to an issue in an optional service, you need to determine if the service is enabled. This can be done through the Service Manager interface, which can be invoked from Services in Administrative Tools.

W4.5 How to Protect against the Windows Services Vulnerabilities

  • Keep the systems updated with all the latest patches and service packs. If possible enable Automatic Updates on all systems.

  • Use Intrusion Prevention/Detection Systems to prevent/detect attacks exploiting these vulnerabilities.

  • In some cases, exposure to the vulnerability could be removed by disabling the corresponding service. For example, Windows Routing and Remote Access service could be disabled in most environments using Windows 2000. To do so, start the service manager interface. Locate the required service and right click it. Invoke the properties option in the popup menu. The "Startup Type" of the service can be modified to disable the respective service.

  • In some cases, null session access to the vulnerable interface could be removed as a work-around. It is a good practice to review your current RestrictAnonymous settings and keep it as stringent as possible based on your environment. http://www.securityfocus.com/infocus/1352

  • Many of these vulnerabilities are found on interfaces offered through CIFS, and blocking ports 139/tcp and 445/tcp at the perimeter is essential for preventing remote attacks. It is also a good practice to block inbound RPC requests from the Internet to ports above 1024 to block attacks to other RPC based vulnerabilities using firewalls.

  • XP SP2 and Windows 2003 SP1 and R2 come with several security enhancements, including the Windows firewall and Security Configuration Wizard (Windows 2003 SP1 and R2 only). It is highly advisable to upgrade to these service packs, enable the Windows firewall and reduce attack surface with Security Configuration Wizard.

W4.6 References

Threats and Countermeasures: Security Settings in Windows Server 2003 and Windows XP
http://www.microsoft.com/technet/security/topics/serversecurity/tcg/tcgch00.mspx

Windows XP Security Guide
http://www.microsoft.com/technet/security/prodtech/windowsxp/secwinxp/default.mspx

Windows Server 2003 Security Guide
http://www.microsoft.com/technet/security/prodtech/windowsserver2003/w2003hg/sgch00.mspx

Using Windows Firewall
http://www.microsoft.com/windowsxp/using/networking/security/winfirewall.mspx

Security Configuration Wizard for Windows Server 2003
http://www.microsoft.com/windowsserver2003/technologies/security/configwiz/default.mspx

How to use IPSec IP filter lists in Windows 2000
http://support.microsoft.com/kb/313190

How to block specific network protocols and ports by using IPSec
http://support.microsoft.com/kb/813878

How to configure TCP/IP filtering in Windows 2000
http://support.microsoft.com/kb/309798

top^

W5 Windows Configuration Weaknesses

W5.1 Description

1. User Configured Password Weaknesses

Weaknesses in password configurations have taken on added importance in recent years with the proliferation of worms, bots, and other malware which have improved their ability to propagate themselves through the abuse of inadequate passwords. Enforcement of complex passwords is one of the oldest issues facing IT security administrators but continues to plague enterprises across the globe. These weaknesses can exist at both the Active Directory and the local level, each of which can be exploited effectively both by malware and by inside threats. In addition, with the increase of cross-platform centralized authentication, compromise of Windows credentials can often lead directly to compromise of credentials for other platforms (i.e. UNIX and RACF/ACF2/Top Secret). Even if complex passwords are enforced on the vast majority of accounts on the network, one weak password can lead to a much larger compromise.

2. Service Account Passwords

Non-system Service accounts need passwords in Windows. Unfortunately, it is still very common to use short, printable passwords for these accounts. This is particularly troublesome as they are often used on many machines, have high privileges, and change rarely.

3. Null Log-on

Null credentials have long been an issue in Windows domain environments. Since the inception of the domain architecture with Windows NT, null sessions have allowed anonymous users to enumerate systems, shares, and user accounts. Windows 2000 introduced two levels of control over anonymous access; however, this control was disabled by default. With the inception of Windows 2003, Microsoft has added a number of controls over anonymous access and enabled some restrictions by default. However, legacy systems have forced many environments to continue to support anonymous connections.

W5.2 How to Protect Against Configuration Weaknesses

Weak Passwords:

  • Enforce a strict password policy for all users on the domain. This policy should include complexity requirements and password expiration. Consider using a 3rd party tool for managing local account passwords and ensuring that passwords are unique.

  • Prevent Windows from storing the LM hash in Active Directory or SAM database by following the instructions posted by Microsoft.

  • Implement a policy to periodically test passwords across the enterprise. This testing should include the use of automated tools such as THC Hydra, LophtCrack and John the Ripper to check for blank and simple/common passwords. The testing should be performed on all platforms and should not be limited to AD passwords.

Null Log-on:

  • Restrict anonymous access to domain systems. See the "References" section for details regarding the impact of null session restrictions and the settings available in various scenarios.

W5.3 References

The Administrator Accounts Security Planning Guide
http://www.microsoft.com/technet/security/topics/serversecurity/administratoraccounts/default.mspx

Windows Security Guides
http://www.microsoft.com/technet/security/prodtech/windowsxp/secwinxp/default.mspx
http://www.microsoft.com/downloads/details.aspx?FamilyID=15E83186-A2C8-4C8F-A9D0-A0201F639A56&DisplayLang=en

How to prevent Windows from storing a LAN manager hash of your password in Active Directory and local SAM databases
http://support.microsoft.com/kb/299656

MSRPC NULL sessions - exploitation and protection
http://www.hsc.fr/ressources/presentations/null_sessions/null_sessions_explained.html

Restricting Anonymous Access
http://technet2.microsoft.com/WindowsServer/en/library/2c82586e-bd58-42b7-9976-228a23721e351033.mspx?mfr=true

Client, service, and program incompatibilities that may occur when you modify security settings and user rights assignments
http://support.microsoft.com/kb/823659

Microsoft policy on third-party security configuration guidance support
http://support.microsoft.com/kb/885409/en-us

top^

M1. Mac OS X

M1.1 Description

Mac OS X is Apple's BSD-based operating system for its line of PowerPC- and Intel-based computers.

For more information on Mac OS X, see: http://www.apple.com/macosx

Mac OS X is made up of many different components. Each of these components could potentially have security flaws. The majority of the critical flaws discovered in the past year fall into six different categories:

  • Safari - Apple's Safari web browser is the default web browser in recent versions of Mac OS X. Vulnerabilities in this application could potentially result in complete control of a user's browser or login session.

  • ImageIO - The core image-handling framework used by the system and most applications. Vulnerabilities in this framework could potentially affect many different applications. Image files are generally considered "safe" files by various applications, and are opened without prompting by default.

  • Unix - Mac OS X is based on and incorporates large amounts of code from earlier Unix-like operating systems. Many applications written for various Unix and Unix-like operating systems run on Mac OS X and some of these applications are shipped as part of the operating system by Apple. Flaws in these applications may be patched for Mac OS X considerably later than for the upstream vendor.

  • Wireless - Reports of a critical vulnerability in Mac OS X's wireless network subsystem that allow physically-proximate attackers to gain complete control of a vulnerable system were met with surprise by many in the security community. The nature of the flaw allowed attackers to attack systems even if that system was not part of the same logical network as the attacker. Additional flaws were discovered in the Bluetooth wireless interface subsystem, with similar results.

  • Virus/Trojan - The first viruses and trojans for the Mac OS X platform were discovered in the past year.

  • Other - The remaining vulnerabilities do not fit in a well-defined category.

Note that Apple normally distributes patches and updates as comprehensive updates; a given Security Update will include both low-severity and critical updates.

M1.2 CVE Entries

Safari Vulnerabilities (includes zero-days)

HTML Rendering Vulnerabilities - CVE-2005-3705, CVE-2006-1987, CVE-2006-3505, CVE-2006-3946

Security Bypass Vulnerabilities - CVE-2005-2516, CVE-2006-0399, CVE-2006-0397, CVE-2006-0398.

ImageIO Vulnerabilities

Image Format Vulnerabilities - CVE-2006-1469, CVE-2006-1982, CVE-2005-2747

3rdParty Products' Vulnerabilities

Inherited Vulnerabilities - CVE-2006-0384

Wireless Driver Vulnerabilities

WiFi Driver Vulnerabilities - CVE-2006-3509, CVE-2006-3508, CVE-2006-3507

Viruses and Trojans

Viruses and Trojans - OSX/Leap-A trojan.

Other Vulnerabilities

CVE-2006-3498, CVE-2006-1450, CVE-2006-1449, CVE-2006-0848, CVE-2005-2518, CVE-2006-4394

M 1.3 How to Determine if You Are at Risk

Any default or unpatched Mac OS X installations should be presumed to be vulnerable.

The following procedure will check if there are new packages available.

  1. Choose System Preferences from the Apple Menu.
  2. Choose Software Update from the View menu.
  3. Click Update Now.
  4. Check the items available

To aid in the process of vulnerability assessment, you can leverage any vulnerability scanner.

M1.4 How to Protect Against These Vulnerabilities

  • Be sure to stay current and have all security updates for Apple products applied by turning on the Software Update System to automatically check for software updates released by Apple. Although different schedules are possible, we recommend that you configure it to check for updates on a weekly basis at least. For more information about how to check and run the Software Update System, see the Apple Software Updates webpage - http://www.apple.com/macosx/upgrade/softwareupdates.html

  • To avoid unauthorized access to your machine, turn on the built-in personal firewall. If you have authorized services running in your machine that need external access, be sure to explicitly permit them.

  • There are many excellent guides available for hardening Mac OS X. The CIS Benchmark for Mac OS X enumerates security configurations useful for hardening the Operating System. The actions suggested by the CIS Level-1 benchmarks documents are unlikely to cause any interruption of service or applications and are highly recommended to be applied on the system. Also, the Securing Mac OS X 10.4 Tiger white paper examines security features and hardening of Mac OS X.

top^

U1. UNIX Configuration Weaknesses

U1.1 Description

Most Unix/Linux systems include a number of standard services in their default installation. These services, even if fully patched, can be the cause of unintended compromises. Security savvy administrators harden systems by turning off unnecessary services and/or firewalling them from the Internet.

For example a default installation of Red Hat Enterprise Linux will have services such as cups (Common Unix Printing System), portmap (RPC support), sendmail (Mail Transport Agent), and sshd (OpenSSH server) which should be disabled if they are not required.

Of particular interest are brute-force attacks against command line access such as SSH, FTP, and telnet. These services are often the target of attacks due to the prevalence of these services for remote access. However over the last couple of years a concerted effort has been made by attackers to brute-force the passwords used by these applications. Increasingly worms and bots have brute force password engines built into them. Systems with weak passwords for user accounts are actively compromised; often privilege escalations are used to gain root access, and root-kits installed to hide the compromise. It is important to remember that brute forcing passwords can be a used as a technique to compromise even a fully patched system.

Security conscious administrators use SSH as their method of interactive remote access. If the version of SSH is current and it is fully patched, the service is generally assumed to be safe. However regardless of whether it is up to date and patched it can still be compromised via brute-force password-guessing attacks. For SSH it is recommended to use public key authentication mechanism to thwart such attacks. For the other interactive services audit passwords to ensure they are of sufficient complexity to resist a brute-force attacks.

U1.2 Affected Versions

All versions of UNIX/Linux are potentially at risk from improper and default configurations. All UNIX/Linux versions may be affected by accounts having weak or dictionary-based passwords for authentication.

U1.3 How to determine if you are vulnerable

Default installations (either from the manufacturer or by an administrator) of operating systems or network applications may introduce a wide range of unneeded and unused services. In many cases the uncertainty about operating system or application needs leads many manufacturers or administrators to install all of the software in case it is needed in the future. This simplifies the installation process significantly but also introduces a wide range of unneeded services and accounts that have default/weak/or known passwords.

The use of an updated vulnerability scanner or a port mapper can be highly effective in diagnosing any potential vulnerabilities left by default installations, such as unneeded and/or outdated services/applications. Also, a password cracker can help to avoid the use of weak passwords, which would make more difficult to guess in case of a brute force attack on remote services.

Please note: Never run a password cracker/vulnerability scanner, even on systems for which you have root-like access, without explicit and preferably written permission from your employer. Administrators with the most benevolent of intentions have been fired for running password cracking tools without authority to do so.

U1.4 How to Protect against These Vulnerabilities

Unnecessary Services

  • Scan the server with a port scanner or vulnerability assessment tool to determine what unnecessary services are running on a system. Disable the services that are not required by any necessary applications.

  • Install the latest vendor patches regularly to mitigate vulnerabilities in exposed services. Patch management is a critical part of the risk management process.

  • Use The Center for Internet Security benchmarks from www.cisecurity.org for your OS and services you use. Also consider using Bastille to harden Linux and HP-UX based hosts from www.bastille-unix.org.

  • Consider moving services from default ports where possible. Automated scanners tend to only scan default ports.

  • Utilize a hardware or software firewall to protect required services.

  • Ensure services are protected by vendor-supplied security mechanisms (for example SELinux or address space randomization).

Brute Force Attacks

  • Don't use default passwords on any accounts.

  • Enforce a strong password policy. Don't permit weak passwords or passwords based on dictionary words.

  • Audit to ensure your password policy is being adhered to.

  • Limit the number of failed login attempts to exposed services.

  • Limit the accounts that can log in over the network; root should not be one of them.

  • Employ firewall rules to limit the source of any remote logins.

  • Prohibit shared accounts and don't use generic account names like tester, guest, sysadmin, admin, etc.

  • Log failed login attempts. A large number of failed logins to a system may require a further check on the system to see if it has been compromised.

  • Consider using certificate based authentication.

  • If your UNIX system allows the use of PAM authentication modules, implement PAM modules that check for password's strength.

  • Firewall services that do not require access to the Internet.

U1.5 References

SSH Brute Force Attacks and Counter Measures

General UNIX Security Resources

top^

C1 Web Applications

C1.1 Description

Applications such as Content Management Systems (CMS), Wikis, Portals, Bulletin Boards, and discussion forums are being used by small and large organizations. Every week hundreds of vulnerabilities are being reported in these web applications, and are being actively exploited. The number of attempted attacks every day for some of the large web hosting farms range from hundreds of thousands to even millions.

All web frameworks (PHP, .NET, J2EE, Ruby on Rails, ColdFusion, Perl, etc) and all types of web applications are at risk from web application security defects, ranging from insufficient validation through to application logic errors. The most exploited vulnerabilities are:

  • PHP Remote File Include: PHP is the most common web application language and framework in use today. By default, PHP allows file functions to access resources on the Internet using a feature called "allow_url_fopen". When PHP scripts allow user input to influence file names, remote file inclusion can be the result. This attack allows (but is not limited to):

    • Remote code execution

    • Remote root kit installation

    • On Windows, internal system compromise may be possible through the use of PHP’s SMB file wrappers

  • SQL Injection: Injections, particularly SQL injections, are common in web applications. Injections are possible due to intermingling of user supplied data within dynamic queries or within poorly constructed stored procedures. SQL injections allow attackers:

    • To create, read, update, or delete any arbitrary data available to the application

    • In the worst case scenario, to completely compromise the database system and systems around it

  • Cross-Site Scripting (XSS): Cross site scripting, better known as XSS, is the most pernicious and easily found web application security issue. XSS allows attackers to deface web sites, insert hostile content, conduct phishing attacks, take over the user’s browser using JavaScript malware, and force users to conduct commands not of their own choosing – an attack known as cross-site request forgeries, better known as CSRF.

  • Cross-site request forgeries (CSRF): CSRF forces legitimate users to execute commands without their consent. This type of attack is extremely hard to prevent unless the application is free of cross-site scripting vectors, including DOM injections. With the rise of Ajax techniques, and better knowledge of how to properly exploit XSS attacks, CSRF attacks are becoming extremely sophisticated, both as an active individual attack and as automated worms, such as the Samy MySpace Worm.

  • Directory Traversal: Directory traversal (file access via ".." or many encoded variants) allows attackers access to controlled resources, such as password files, configuration files, database credentials or other files of the attacker’s choosing.

C1.2 How to Determine If You Are at Risk

Web scanning tools can help find these vulnerabilities, particularly if they are known bugs. However, to find all potential vulnerabilities requires a source code review. This should be done by the developers prior to release.

Inspect your web application framework's configuration and harden appropriately.

System administrators should consider scanning web servers periodically with vulnerability scanners, particularly if they run a large diverse range of user supplied scripts, such as a hosting farm. It is impractical for system administrators to perform detailed penetration tests.

C1.3 How to Protect against Web Application Vulnerabilities

From the PHP system administration and hosting perspective:
  • Upgrade to PHP 5.2 as it eliminates many latent PHP security issues and allows for safer API, such as PDO
  • Always test and deploy patches and new versions of PHP as they are released
  • Frequent web scanning is recommended in environments where a large number of PHP applications are in use
  • Consider using the following PHP configuration:
    • register_globals (should be off, will break insecure apps)
    • allow_url_fopen (should be off, will break apps that rely on this feature, but protect against a very active exploit vector)
    • magic_quotes_gpc (should be off, will break older insecure apps)
    • open_basedir (should be enabled and correctly configured)
    • Consider using least privilege execution features like PHPsuexec or suPHP
    • Consider using Suhosin to control the execution environment of PHP scripts
  • Use Intrusion Prevention/Detection Systems to block/alert on malicious HTTP requests. Consider using Apache's mod_security to block known PHP attacks
  • As a last resort, consider banning applications which have a track record of active exploitation, and slow response times to fix known security issues.
From the developer perspective:
  • If you use PHP, migrate your application to PHP 5.2 as a matter of urgency.
  • To avoid the coding issues above:
    • Develop with the latest PHP release and a hardened configuration (see above)
    • Validate all input appropriately
    • Encode all output using htmlentities() or a similar mechanism to avoid XSS attacks
    • Migrate your data layer to PDO - do not use the old style mysql_*() functions as they are known faulty
    • Do not use user-supplied input with file functions to avoid remote file inclusion attacks
  • Join secure coding organizations, such as OWASP (see references) to boost skills, and learn about secure coding
  • Test your apps using the OWASP Testing Guide with tools like WebScarab, Firefox's Web Developer Toolbar, Greasemonkey and the XSS Assistant

C1.4 References

OWASP - Open Web Application Security Project
http://www.owasp.org

OWASP Testing Guide
http://www.owasp.org/index.php/OWASP_Testing_Guide_v2_Table_of_Contents

OWASP Guide - a compendium of secure coding
http://www.owasp.org/index.php/Category:OWASP_Guide_Project

OWASP Top 10 - Top 10 web application security weaknesses
http://www.owasp.org/index.php/Category:OWASP_Top_Ten_Project

Suhosin, a Hardened PHP project to control the execution environment of PHP applications
http://www.hardened-php.net/suhosin/

PHP Security Features
http://php.net/features.safe-mode

top^

C2. Database Software

C2.1 Description

Databases are a key element of many systems storing, searching or manipulating large amounts of data. They are found in virtually all businesses, financial, banking, customer relationship and system monitoring applications.

Due to the valuable information they store such as personal or financial details, databases are often a target of attack and are of particular interest to identity thieves. Database systems are often very complex, combining the core database with a collection of applications; some supplied by the database vendor, others written in house (such as web applications). A flaw in any of these components can compromise the stored data. The most common vulnerabilities in database systems can be classified as:

  • Use of default configurations with default user names and passwords.
  • Buffer overflows in processes that listen on well known TCP/UDP ports.
  • SQL Injection via the database's own tools or web front-ends added by users.
  • Use of weak passwords for privileged accounts

There are many different database systems available. Some of the most common are Microsoft SQL Server (proprietary, runs on Windows), Oracle (proprietary, runs on many platforms), IBM DB2 and IBM Informix (both proprietary, run on multiple platforms), Sybase (proprietary, runs on many platforms), MySQL and PostgreSQL (both open source and available on many platforms).

All modern relational database systems are port addressable, which means that anyone with readily available query tools can attempt to connect directly to the database, bypassing security mechanisms used by the operating system. The commonly used default connections are: Microsoft SQL via TCP port 1433 and UDP port 1434, Oracle via TCP port 1521, IBM DB2 via ports 523 and 50000 up, IBM Informix via TCP ports 9088 and 9099, MySQL via TCP port 3306, and PostgreSQL via TCP port 5432.

Proof of concept exploits for many database flaws are readily available on the Internet. Due to the network connections they provide, databases may suffer from worms. The most infamous of these was the SQL Slammer worm in 2003. 2005 saw the appearance of the first Oracle worm: "Voyager" . Whilst this did not carry a damaging payload, it demonstrated what could be done if an Oracle database is not protected.

In addition to addressing the specific vulnerabilities mentioned here, administrators concerned with database security should consider:

  • The impact of standards such as the Payment Card Industry Data Security Standard that may require encryption of some information such as credit card numbers.
  • The risks of transferring large quantities of data onto mobile devices: in the last year there have been numerous reports of personal data being lost through the theft of laptops.

C2.2 Operating Systems Affected

Most database systems, commercial and open source, run on multiple platforms. Issues regularly cover all supported platforms.

C2.3 CVE Entries

These are the entries released since October 2005. Earlier vulnerabilities can be found in previous editions of the SANS vulnerabilities lists. In many cases reported issues are not flaws in the databases themselves but in applications build around them, e.g. SQL injection into web interfaces; these have not been included here.

Oracle
CVE-2005-3641, CVE-2006-0256, CVE-2006-0257, CVE-2006-0258, CVE-2006-0259, CVE-2006-0260, CVE-2006-0261, CVE-2006-0262, CVE-2006-0263, CVE-2006-0265, CVE-2006-0266, CVE-2006-0267, CVE-2006-0268, CVE-2006-0269, CVE-2006-0270, CVE-2006-0271, CVE-2006-0272, CVE-2006-0282, CVE-2006-0283, CVE-2006-0285, CVE-2006-0286, CVE-2006-0287, CVE-2006-0290, CVE-2006-0291, CVE-2006-0435, CVE-2006-0547, CVE-2006-0548, CVE-2006-0549, CVE-2006-0551, CVE-2006-0552, CVE-2006-0586, CVE-2006-1868, CVE-2006-1871, CVE-2006-1872, CVE-2006-1873, CVE-2006-1874, CVE-2006-3698.

Note: This list concentrates on the core Oracle database programs. There are vulnerabilities in other applications that form part of the Oracle suite. Oracle releases quarterly Critical Patch Updates (CPU) covering large numbers of issues in the databases and associated applications. The general advice is to work through these CPUs. Due to the way Oracle released information during this reporting period multiple CVE entries may be reporting a single issue.

MySQL
CVE-2006-2753.
PostgreSQL
CVE-2006-2313, CVE-2006-2314.
IBM DB2
CVE-2005-3643, CVE-2005-4737.
IBM Informix
CVE-2005-3642, CVE-2006-3854, CVE-2006-3860, CVE-2006-3862.
Microsoft SQL Server
None during this reporting period.
Sybase
None during this reporting period.

C2.4 How to Determine If You Are Vulnerable

It is not sufficient to check a simple, manually maintained list of the applications that have been installed! Because databases are often distributed as components of other applications, it is possible for a database to have been installed without administrators realizing it. Databases may therefore remain unpatched or in vulnerable default configurations. This was graphically demonstrated when the SQL Slammer worm attacked the Microsoft Data Access Component (MDAC), which is included in many applications.

Perform a vulnerability scan on systems to determine whether DBMS software is available, accessible and vulnerable. You can use general vulnerability scanners or tools from database vendors such as MySQL Network Scanner, Microsoft SQL server tool. The Microsoft Baseline Security Analyzer is also of use for Microsoft SQL Server

C2.5 How to Protect Against Database Vulnerabilities

C2.6 References

Generic and multiple database resources
Oracle
MySQL
PostgreSQL Security Guide
Microsoft SQL Security
IBM DB2
IBM Informix
Sybase
top^

C3. P2P File Sharing Applications

C3.1 Description

Peer to Peer networks consist of collections of computers or “nodes” that simultaneously function as both “clients” and “servers” to achieve a common purpose. The nodes may exchange data, share resources, provide directory services, support communications and provide real time collaboration tools.

A number of control and communication architectures are utilized. Centralized index servers can provide directory services for data and service availability. In fully distributed networks each node helps with the indexing and directory services and is fully equivalent. Hybrid architectures combine the features of both to different degrees and groups of nodes may “elect/promote” certain nodes to act as regional index/directory servers.

Many legitimate applications use P2P. Software tool vendors, including Microsoft and Sun, provide a variety of tools and encourage development of P2P applications. However, like any data transfer tool, P2P applications can be misused or exploited to illegally share copyrighted material, obtain confidential data, expose users to unwanted pornography, violence or propaganda, distribute and execute malware (viruses, spyware, bots, etc.), overload the network, mine usage and behavior patterns and control bots, all of which can create a legal liability. The liability and legal prosecution may not be limited to the perpetrator and may be extended to the network sponsor, supporters or members.

The P2P networks themselves may be attacked by modifying legitimate files with malware, seeding malware files into shared directories, exploiting vulnerabilities in the protocol or errors in coding, blocking (filtering) the protocol, denial of service by making the network function slowly, spamming and identity attacks that identify network users and harass them. Legal action has been successfully used to shut down some popular networks that were culprits of copyright infringement.

P2P concepts and techniques are evolving and can be found in:

  • File sharing networks—whose main goal is to share resources such as storage and bandwidth. These operate through a distributed network of clients, sharing directories of files or entire hard drives of data. Clients participate by downloading files from other users, making their data available to others and coordinating file searches for other users.

  • Cloud Computing —(Also called distributed processing, Grid Computing, mesh networks) where “clouds” of computers are deployed to provide a virtual computing environment to accomplish a given task by distributing processing load and data. Cloud Computing brings servers on-line as needed, and the end user does not know where the data resides or executes at any point. In some cases, the application runs on a combination of servers and on the user’s PC. Server clouds can reside physically in large facilities controlled by one organization or they can also reside all over the Internet. Because resizable computing capacity is based on virtual servers the data owner does not really know where his programs and data reside physically.

Most of the P2P programs use a set of default ports but they can automatically or manually be set to use different ports if necessary to circumvent detection, firewalls, or egress filters. The trend seems to be moving towards the use of http wrappers and encryption to easily bypass corporate restrictions.

C3.2 Operating Systems Affected

There are versions of P2P software available for all Microsoft Windows operating systems currently in use, along with versions for Linux, MacOS and most Unix-like Operating Systems.

C3.3 Detecting P2P activity

Detecting P2P activity on the network can prove to be challenging. It is possible to detect P2P software running on your network by:

  • Monitoring traffic for common ports used by P2P software works with some well known older programs. However, some programs have moved on to using http, https and other ports that commonly need to be passed through firewalls and proxies.

  • Application layer monitoring for P2P protocols can identify programs that use commonly allowed ports (53, 80). However, it fails when more malicious programs encrypt the payload.

  • Some host based intrusion prevention software and system change auditing tools can prevent the installation or execution of P2P applications along with other malware.

  • Pattern matching / behavioral Intrusion Detection systems can identify potential P2P members. Patterns observed include frequency, timing and size of communication bursts.

  • Scanning network and PC storage for content commonly downloaded by P2P users, including *.mp3, *.wma, *.avi, *.mpg, *.mpeg, *.jpg, *.gif, *.zip, *.torrent, and *.exe.

  • Changes in network performance may indicate exploding P2P usage, or malware infections.

  • Some Firewalls and Intrusion Detection/Prevention products combine detection techniques to detect/prevent P2P traffic from entering or leaving the network.

  • For Microsoft Windows machines, SMS can be used to scan for executables that are installed on workstations. Furthermore, administrators should limit permissions in order to prevent users from installing such software on their workstations.

  • Compromised systems that have malware installed via P2P file sharing will display the same symptoms seen when other means of malware distribution are successful.

C3.4 How to Protect against P2P Software Vulnerabilities

  • Standard users should not be permitted to install software. Restrict Administrative and Power User level privileges to support personnel acting in their support capacity. If a user must have Administrative or Power User privileges, create a separate account to be used for his/her daily office functions, internet surfing and on-line communication.

  • Use tools such as Microsoft DropMyRights for securing Web browsers and mail clients.

  • In Active Directory environments, Software Restriction Group Policies can be used in order to block known types of binaries from execution.

  • Educate users about P2P networks, the dangers of file sharing and company policy.

  • Turn on Egress filtering to restrict any ports not required for business purposes, although as more P2P applications move to http and encryption, this will prove less effective.

  • Monitor firewall and IDS logs.

  • To reduce malware infections which can be spread through numerous applications, use enterprise-wide anti-virus and antispyware products and ensure that updates are performed daily.

  • Use host-based firewalls in addition to perimeter firewalls. Windows XP and Windows 2003 include Windows firewall, which provides adequate protection if properly configured. A variety of third-party host based firewalls (ZoneAlarm, Sygate, Outpost) provide additional functionality and flexibility. Windows 2000, XP and 2003 systems can use IPSec policies in order to provide port filtering of unnecessary network traffic over VPN. In Active Directory environments, IPSec policies and Windows Firewall configuration (for Windows XP SP2 and Windows 2003 SP1) can be managed centrally through Group Policies.

  • Disable the Simple File Sharing feature of Windows XP if not explicitly required. [Start - Settings -Control Panel - Folder Options - Tab View - Disable (uncheck) setting Use Simple File Sharing - Apply - OK. ]

  • Monitor systems for presence of unknown executables and unauthorized modification of system files. Software products like Tripwire or AIDE (there are commercial and open source versions of the product) can be used to detect changes in files.

  • Samba-based shares can be configured to run a filter upon opening or saving of files. A filetype detector and alerting system could prove useful to avoid misusage of shares.

C3.5 References

Wikipedia Peer-to-peer
http://en.wikipedia.org/wiki/Peer-to-peer

Department of Justice Cybercrime web site
http://www.usdoj.gov/criminal/cybercrime

Other software providers could be held secondarily liable for copyright infringement.
http://www.usdoj.gov/criminal/cybercrime/2006IPTFProgressReport(6-19-06).pdf FBI Education initiative
http://www.fbi.gov/cyberinvest/cyberedletter.htm

The Information Factories
http://www.wired.com/wired/archive/14.10/cloudware_pr.html

Mobile Service Clouds: A Self-managing Infrastructure for Autonomic Mobile Computing Services
http://www.cse.msu.edu/~farshad/publications/conferences/samimi06msc.pdf

Cyber Security Tip ST05-007 - Risks of File-Sharing Technology
http://www.us-cert.gov/cas/tips/ST05-007.html

Risks of P2P File Sharing (Presentation)
http://www.ftc.gov/bcp/workshops/filesharing/presentations/hale.pdf

Securing Windows XP Professional in a Peer-to-Peer Networking Environment
http://www.microsoft.com/technet/security/smallbusiness/prodtech/windowsxp/sec_winxp_pro_p2p.mspx

Identifying P2P users using traffic analysis - Yiming Gong - 2005-07-21
http://www.securityfocus.com/infocus/1843

Bot software looks to improve peerage
http://www.securityfocus.com/news/11390

Stop the bots
http://www.securityfocus.com/columnists/398/1

How to block specific network protocols and ports by using IPSec (MS KB article 813878)
http://support.microsoft.com/kb/813878

Using Software Restriction Policies to Protect Against Unauthorized Software
http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/rstrplcy.mspx

Availability and description of the Port Reporter tool (MS KB article 837243)
http://support.microsoft.com/kb/837243

New features and functionality in PortQry version 2.0 (MS KB article 832919)
http://support.microsoft.com/default.aspx?kbid=832919

Log Parser 2.2
http://www.microsoft.com/technet/scriptcenter/tools/logparser/default.mspx

Browsing the Web and Reading E-mail Safely as an Administrator (DropMyRights)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncode/html/secure11152004.asp

Amazon Cloud Computing goes beta
http://www.amazon.com/gp/browse.html?node=201590011

Checkpoint Application Intelligence
http://www.checkpoint.com/products/downloads/applicationintelligence_whitepaper.pdf

Microsoft site search for peer-to-peer
http://search.msdn.microsoft.com/search/default.aspx?siteId=0&tab=0&query=peer-to-peer

Instant-Messaging-and-P2P-Vulnerabilities-for-Health-Organizations
http://ezinearticles.com/?Instant-Messaging-and-P2P-Vulnerabilities-for-Health-Organizations&id=232800

Detecting and Understanding Rootkits
http://www.buanzo.com.ar/sec/Rootkits.html

Application Layer Packet Classifier for Linux
http://l7-filter.sourceforge.net/

top^

C4. Instant Messaging

C4.1 Description

The widespread use of instant messaging (IM) continues to increase the security risks for both organizations and individual users. While instant messaging can be a very useful communication tool, it is also subject to many security concerns. Recent attacks include new variations in the establishment and spread of botnets, and the use of compromised instant messaging accounts to lure users into revealing sensitive information. Variants of e-mail worms (such as the Mytob family) have also been spread through the use of instant messaging. The general risk areas related to instant messaging are:

  • Malware -- Worms, viruses, and Trojans transferred through the use of instant messaging. Many bots are controlled via IRC channels.

  • Information confidentiality -- Information transferred via instant messaging can be subject to disclosure along any part of the process.

  • Network -- Denial of service attacks; excessive network capacity utilization, even through legitimate use.

  • Application vulnerabilities -- Instant messaging applications contain vulnerabilities that can be exploited to compromise affected systems.

Popular instant message applications include: AOL Instant Messenger (AIM), Gaim, ICQ, Jabber Messenger, Lotus Sametime, Skype, QQ, Windows Live Messenger (WLM), Google Talk, Trillian and Yahoo! Messenger. Instant messaging protocols include: IRC, MSNP, OSCAR, SIMPLE, XMPP and YMSG.

C4.2 Affected Operating Systems

Instant messaging applications are available for all popular operating systems.

C4.3 CVE Entries

CVE-2006-0992, CVE-2006-4662, CVE-2006-5084

C4.4 How to Protect against IM Vulnerabilities and Unauthorized IM Usage

  • Establish policies for acceptable use of instant messaging and ensure that all users are aware of those policies and clearly understand the potential risks.

  • Standard users should not be permitted to install software. Restrict Administrative and Power User level privileges to support personnel acting in their support capacity. If a user must have Administrative or Power User privileges, create a separate account to be used for his/her daily office functions, internet surfing and on-line communication.

  • Ensure that vendor patches are promptly applied to instant messaging software, interrelated applications, and the underlying operating system.

  • Employ antivirus and antispyware products.

  • Do not rely on external IM servers for internal use of instant messaging;Provide a commercial grade IM proxy or internal IM server.

  • Create secure communications paths when using instant messaging with trusted business partners.

  • Appropriately configure intrusion detection/prevention systems. Understand that many instant messaging applications are capable of enabling associated communications to masquerade as otherwise legitimate traffic (e.g. http).

  • Consider deploying products specifically designed for instant messaging security.

  • Filter all http traffic through an authenticating proxy server to provide additional capabilities of filtering/monitoring instant messaging traffic.

  • Block access to known public instant messaging servers that have not been explicitly authorized. (Note: Offers only partial protection due to the number of potential external servers.)

  • Block popular instant messaging ports. (Note: Offers only partial protection, due to the number of potential protocols and associated ports, and the ability of applications to bypass port restrictions.)

  • Monitor using an Intrusion Detection/Prevention system for users creating tunnels for IM or bypassing proxies.

C4.5 References

Phishers hijack IM accounts
http://news.com.com/Phishers+hijack+IM+accounts/2100-7349_3-6126367.html

Rich presence: a new user communications experience
http://www.alcatel.com/doctypes/articlepaperlibrary/html/ATR2005Q1/ATR2005Q1A17_EN.jhtml

Instant messaging: a new target for hackers
http://www.leavcom.com/ieee_july05.htm

AIM bot creates "fight combos" to spread
http://www.securityfocus.com/brief/305

Secure Instant Messaging in the Enterprise
http://searchsecurity.techtarget.com/tip/0,289483,sid14_gci1199405,00.html

top^

C5. Media Players

C5.1 Description

Media players are popularly used and have an install base of millions of systems. Content is downloaded in the form of multimedia files such as movies, video or music. This content is embedded into Web pages, presentations, or integrated into multimedia applications.

Media players can end up on systems through default installations or bundled with other software. Typically browsers are set up to "conveniently" download and open media files without requiring user interaction. They are also downloaded by users on corporate networks to facilitate transfer of multimedia content to their mobile devices.

A number of vulnerabilities have been discovered in various media players over the last year. Many of these vulnerabilities allow a malicious webpage or a media file to completely compromise a user's system without requiring much user interaction. The user's system can be compromised simply upon visiting a malicious webpage. Hence, these vulnerabilities can be exploited to install malicious software like spyware, Trojans, adware or keyloggers on users' systems. Exploit code is publicly available in many instances.

Some of the more popular media players include:

  • Windows: Windows Media Player, RealPlayer, Apple Quicktime, Winamp, iTunes
  • Mac OS: RealPlayer, Quicktime, iTunes
  • Linux/Unix: RealPlayer, Helix Player

C5.2 Operating Systems Affected

  • Microsoft Windows
  • Linux/UNIX
  • Mac OS X

C5.3 CVE Entries

RealPlayer and Helix Player
CVE-2006-1370, CVE-2006-0323, CVE-2005-2922, CVE-2005-4130, CVE-2005-4126, CVE-2005-3677, CVE-2005-2936
iTunes
CVE-2006-1249, CVE-2005-4092, CVE-2005-2938
Winamp
CVE-2006-0708, CVE-2005-3188, CVE-2005-2310
Quicktime
CVE-2006-2238, CVE-2006-1456, CVE-2006-1249, CVE-2005-3713, CVE-2005-3711, CVE-2005-3710, CVE-2005-3709, CVE-2005-3708, CVE-2005-3707, CVE-2005-2340, CVE-2005-4092, CVE-2005-2743

Windows Media Player

CVE-2006-0025, CVE-2006-0006, CVE-2005-3591
Macromedia Flash Player
CVE-2005-3591, CVE-2005-2628

C5.4 How to Determine If You Are Vulnerable

If you run any of these players, and you are not running the most recent version with all applicable patches, you are vulnerable to the associated attacks. Periodic system reviews of installed software can be used to track unintended media player installations as well as rogue user installations.

C5.5 How to Protect Against Media Player Vulnerabilities

Following are some common approaches to protect against these vulnerabilities:

  • Keep the media players updated with all the latest patches. Most players support updating via the help or tools menus.

  • Carefully review default installations of operating systems and other products to ensure they do not include unwanted media players. Configure operating systems and browsers to prevent unintentional installation.

  • Use Intrusion Prevention/Detection Systems and Anti-virus and Malware Detection Software to block malicious media files.

  • On corporate desktops limit installation of user downloaded software whenever possible. This will allow for better patch management and vulnerability management.

  • Don't install media players on systems where media is not to be played (e.g. servers)

C5.6 References

RealNetworks Media Player Products Home Page
http://www.realnetworks.com/products/media_players.html

Security Reports
http://service.real.com/help/faq/security/
http://www.sans.org/newsletters/risk/display.php?v=4&i=40#widely1
http://www.sans.org/newsletters/risk/display.php?v=4&i=39#widely2
http://www.sans.org/newsletters/risk/display.php?v=4&i=25#widely2

Helix Player Home Page
https://player.helixcommunity.org/

News, Including Security Announcements
https://helixcommunity.org/news/

Security Reports
http://www.sans.org/newsletters/risk/display.php?v=4&i=40#widely1
http://www.sans.org/newsletters/risk/display.php?v=4&i=39#widely2
http://www.sans.org/newsletters/risk/display.php?v=4&i=25#widely2

Apple QuickTime Home Page
http://www.apple.com/quicktime/

Apple iTunes Home Page
http://www.apple.com/itunes/

Apple Security Updates
http://docs.info.apple.com/article.html?artnum=61798

QuickTime Support
http://www.apple.com/support/quicktime/

Security Reports
http://www.sans.org/newsletters/risk/display.php?v=5&i=39#06.39.25
http://www.sans.org/newsletters/risk/display.php?v=5&i=37#widely1
http://www.sans.org/newsletters/risk/display.php?v=5&i=27#06.27.34