Microsoft Windows contains a vulnerability in the Active Directory component that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Description
Microsoft Windows contains a vulnerability in the Active Directory component that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability exists due to errors in processing malformed Lightweight Directory Access Protocol (LDAP) or LDAP over SSL (LDAPS) requests. An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious LDAP request to the vulnerable system. If successful, the attacker could cause Active Directory services to stop responding, resulting in a DoS condition.
Microsoft has confirmed this vulnerability in a security bulletin and released software updates that correct it.
Warning Indicators
The following Microsoft systems are vulnerable when running Active Directory:
Windows 2000 SP4 and prior
Windows Server 2003 SP2 and prior
Windows Server 2003 x64 Edition SP2 and prior
Windows Server 2003 for Itanium-based Systems SP2 and prior
Windows Server 2008 for 32-bit Systems SP2 and prior
Windows Server 2008 for x64-based Systems SP2 and prior
The following Microsoft systems are vulnerable when running Active Directory Application Mode:
Windows XP SP3 and SP2
Windows XP Professional x64 Edition SP2
Windows Server 2003 SP2 and prior
Windows Server 2003 x64 Edition SP2 and prior
IntelliShield Analysis
Active Directory systems often do not require authentication prior to accepting LDAP requests. However, an attacker may require access to trusted, internal networks in order to send a malicious LDAP request to a vulnerable system.
An exploit could allow the attacker to cause Active Directory to stop responding to requests. Client systems that depend on Active Directory services may be unable to access network resources as the result of a DoS condition.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the November 2009 security bulletin release. This Cisco bulletin, which assists administrators in identifying or mitigating these vulnerabilities using Cisco devices, is available at the following link: Cisco Applied Mitigation Bulletin: Microsoft Security Bulletin Release for November 2009
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS09-066
Impact
An unauthenticated, remote attacker could exploit this vulnerability to cause Active Directory services to stop responding, resulting in a DoS condition.
Technical Information
This vulnerability exists due to errors in processing malformed LDAP or LDAPS requests. An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious request to the target system. The processing of malicious requests by the Local Security Authority Subsystem Service could exhaust available space in the memory stack. The stack exhaustion could cause Active Directory to become unresponsive, resulting in a DoS condition.
Safeguards
Administrators are advised to apply the available software updates.
Administrators are advised to restrict network access to affected systems.
Administrators are advised to monitor critical systems.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
Patches/Software
Microsoft customers can obtain updates directly by using the links in the security bulletin. These updates are also distributed by Windows automatic update features and available on the Windows Update website. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
Signatures
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
Datacenter Edition Base, SP1, SP2 | Datacenter Edition, 64-bit Base, SP1, SP2 | Enterprise Edition Base, SP1, SP2 | Enterprise Edition, 64-bit Base, SP1, SP2 | Essential Business Server Premium Base, SP1, SP2 | Essential Business Server Premium, 64-bit Base, SP1, SP2 | Essential Business Server Standard Base, SP1, SP2 | Itanium-Based Systems Edition Base, SP1 | Standard Edition Base, SP1, SP2 | Standard Edition, 64-bit Base, SP1, SP2 | Web Server Base, SP1, SP2 | Web Server, 64-bit Base, SP1, SP2
Microsoft, Inc.
Windows XP
Home Edition SP2, SP3 | Professional Edition SP2, SP3 | Professional x64 (AMD/EM64T) SP2
Associated Products:
N/A
Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the
Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service.
This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment. Cisco is pleased to offer a free trial of the service.
To register for full access, please visit the IntelliShield trial registration page.
LEGAL DISCLAIMER The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
