Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on the targeted system.
The vulnerability exists because the affected operating systems incorrectly process .lnk files. An unauthenticated, remote attacker could exploit the vulnerability by including a crafted .lnk file on local drives or on a remote shared web resource and then persuading a user to browse to the directory of this .lnk file. Successful exploitation could allow the attacker to execute arbitrary code.
A functional exploit that is a part of the Metasploit framework is publicly available.
Microsoft has confirmed this vulnerability and released updated software.
Indicators of Compromise
Information about the affected products is available from the vendor advisory in the Vendor Announcements section of this alert.
The vulnerability is in the Windows Shell component of the Microsoft Windows operating system as a result of incorrect processing when acquiring icons for .lnk files.
An unauthenticated, remote attacker could exploit the vulnerability through a malicious .lnk file on local drives or a Web-based Distributed Authoring and Versioning (WebDAV) resource and persuading a targeted user to browse to the location of this file using a file manager such as Windows Explorer. The crafted .lnk file could specify a path name to locally stored or remotely hosted executable files that could be automatically executed. A successful exploit could allow the attacker to execute arbitrary code by means of the file to which this crafted .lnk file is linked.
Reports suggest that this vulnerability is being exploited in the wild via the stuxnet botnet. This malware reportedly targets industrial control systems. Further information about the malware that exploits the vulnerability is available in Alert 20915.
A functional exploit that is a part of the Metasploit framework demonstrates exploitation of this vulnerability, wherein the crafted .lnk file could link to a WebDAV share. As a result, an attacker could reference any remote web resource and the control of malware is not confined to local drives. This factor could make the exploit much easier and is more likely to be used as an attack vector because the attacker does not need to ensure that malicious code exists on the targeted system.
Reports suggest that documents and web pages embedded with .lnk files could be used as an attack vector to exploit this vulnerability.
Limited user interaction is needed to exploit the vulnerability. By default, Microsoft Windows systems have the AutoRun/AutoPlay features enabled for USB media that could cause Windows Explorer to automatically open the location of the crafted .lnk file, reducing user interaction to simply inserting the USB media on a system. This factor could increase the impact of this vulnerability.
Administrators are advised to apply the appropriate updates.
Administrators are advised to configure antivirus software to scan media upon insertion.
Administrators may also consider disallowing USB drives or other removable media from sensitive environments.
Users are advised not to plug in USB drives from unknown sources.
Microsoft has released a security bulletin at the following link: MS10-046
Microsoft has re-released a security advisory at the following link: 2286198
US-CERT has released a vulnerability note at the following link: VU#940193
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.
The CVSS score for this alert has been modified to reflect higher exploitability. Information about the malware that exploits this vulnerability is also available.
2010-September-11 04:49 GMT
Microsoft has released a security bulletin and updates to address the Windows .lnk file processing arbitrary code execution vulnerability.
2010-August-02 18:22 GMT
Microsoft has re-released a security bulletin with updated workarounds and additional information about attack vectors used to exploit the Microsoft Windows .lnk file processing arbitrary code execution vulnerability.
2010-July-21 15:45 GMT
A Metasploit functional exploit demonstrates exploitation of the Microsoft Windows .lnk file processing arbitrary code execution vulnerability via a remote WebDAV share.
2010-July-20 15:13 GMT
Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code. Updates are not available.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.