Overview 
This month, Microsoft released four patches that repair a total of four vulnerabilities. Two of these patches address remote code execution vulnerabilities, one patch addresses an elevation of privilege vulnerability, and one patch addresses a denial of service vulnerability.


Administrators should patch MS11-083 immediately to prevent exploitation by attackers. Next, administrators should patch MS11-085 and MS11-086 as soon as possible. Lastly, administrators should patch MS11-084 at their earliest convenience.

As always, eEye suggests that all users apply Microsoft patches as fast as possible, preferably after testing the impact on internal applications and network continuity. For those who would like further information regarding the potential risks and remediation requirements of the patches announced today, please consider attending tomorrow's Vulnerability Expert Forum hosted by the eEye Security Research Team. Register Now >>

Vulnerability Expert Forum (VEF)

 

The eEye Research Team

 

Wednesday November 9th 

1pm PT / 4pm ET / 8pm GMT
 

 

MS11-083
Vulnerability in TCP/IP Could Allow Remote Code Execution (2588516)
Microsoft Rating: Critical
CVE: CVE-2011-2013

Analysis
This bulletin addresses a privately reported remote code execution vulnerability in the Windows TCP/IP stack. The patch fixes an integer overflow vulnerability that occurs when processing a continuous stream of UDP packets to a closed port. An attacker that successfully exploited this vulnerability would gain kernel level access to the target machine.

Recommendations
Install the patch immediately to prevent exploitation by attackers. Until the patch can be installed, any unused UDP ports should be blocked at the external firewall.


MS11-084
Vulnerability in Windows Kernel-Mode Drivers Could Allow Denial of Service (2617657)
Microsoft Rating: Moderate
CVE: CVE-2011-2004

Analysis
This bulletin addresses a privately reported denial of service vulnerability in the Windows Kernel. The patch fixes a failure to properly validate an array index when parsing TrueType files. A local attacker that successfully exploited this vulnerability would cause the affected system to crash and restart.

Recommendations
Deploy patches at the earliest convenience. Until the patch can be installed, block ports 139 and 445 using a firewall, prevent the WebClient service from running, and disable both the Preview and Details Pane in Windows Explorer.


MS11-085
Vulnerability in Windows Mail and Windows Meeting Space Could Allow Remote Code Execution (2620704)
Microsoft Rating: Important
CVE: CVE-2011-2016

Analysis
This bulletin addresses a privately reported elevation of privilege vulnerability in Active Directory. The patch fixes a logic vulnerability that occurs when Active Directory, using LDAPS, does not properly validate an SSL certificate's revocation status. An attacker that successfully exploited this vulnerability would gain access, with the associated user’s rights, to resources on the network or any other resource that utilizes the affected LDAP server for authentication.

Recommendations
Deploy patches as soon as possible. Until the patch can be installed, block ports 139 and 445 using a firewall, prevent the WebClient service from running, and prevent DLLs from being loaded from WebDAV and remote shares.


MS11-086
Vulnerability in Active Directory Could Allow Elevation of Privilege (2630837)
Microsoft Rating: Important
CVE: CVE-2011-2014

Analysis
This bulletin addresses a privately reported elevation of privilege vulnerability in Active Directory. The patch fixes a logic vulnerability that occurs when Active Directory, using LDAPS, does not properly validate an SSL certificate's revocation status. An attacker that successfully exploited this vulnerability would gain access to resources on the network or gain the ability to execute remote arbitrary code with the same permissions as the LDAP user that is associated with the revoked certificate.

Recommendations
Deploy patches as soon as possible. Until the patch can be installed, remove the user account that is associated with the revoked certificate. Also, use LDAPS along with IPsec-based connections that are in "Always check CRL" mode.