A security vulnerability, assigned the identifier CVE-2022-41086, has recently been disclosed, detailing a Windows Group Policy elevation of privilege issue that could lead to unintended consequences for IT administrators and sysadmins. This vulnerability is different from the previously published CVE-2022-37992, implying that affected organizations may not be aware that the issue hasn't been mitigated yet.

In this long-read post, we will delve into the technical aspects of CVE-2022-41086 – discussing the code snippets associated with exploitation, links to original references, and how the vulnerability could be exploited by a malicious attacker. By the end of this post, you'll have a comprehensive understanding of CVE-2022-41086 and how it differs from CVE-2022-37992.

Code Snippets

The vulnerability arises from the way Windows processes some Group Policy Objects (GPO). In particular, it involves the manner in which Windows handles a specific set of GPO permissions.

A potential attacker could exploit this vulnerability by creating a specially crafted GPO and gain elevated privileges, allowing them to execute code, install software, and modify system settings.

To exemplify the concept, consider the following PowerShell script as a representation of the exploit:

Import-Module ActiveDirectory
$ExploitedGPOName = "HarmfulGPO"
$NewGPO = New-GPO -Name $ExploitedGPOName
$GPOPath = "LDAP://CN=$($NewGPO.Id),CN=Policies,CN=System,$(([ADSI]'LDAP://RootDSE').rootDomainNamingContext)"
$GPOModify = [ADSI]$GPOPath
$GPOModify.Put("gPCMachineExtensionNames", "PotentialMaliciousExtension")
$GPOModify.SetInfo()

This example represents the creation of a new GPO, named "HarmfulGPO," with a potentially malicious extension included. This may allow an attacker to alter system behavior, enabling them to perform actions that they should not have the privilege to do.

For more information on this vulnerability, refer to the following resources

1. Microsoft's Security Advisory – Details on CVE-2022-41086
2. National Vulnerability Database – CVE-2022-41086 Summary

Identify a vulnerable domain with sufficient privileges to create GPOs.

2. Utilize a malicious GPO (like the one demonstrated in the code snippet above) that could potentially alter system behavior or grant them elevated privileges.

Monitor and manipulate the GPO propagation and processing, targeting specific machines or users.

4. Execute arbitrary code or commands on the targeted machines/users with the elevated privileges enabled by the vulnerability.

Mitigation

As a temporary workaround, administrators should validate the permissions of existing GPOs to ensure they aren't being abused maliciously. Additionally, IT administrators should check for any new or unexpected GPOs within their environment.

At the time of writing, Microsoft is still working on providing an official patch for this vulnerability (CVE-2022-41086). It is crucial to follow Microsoft's Security Advisory to stay informed about the progress of this patch and apply it as soon as it becomes available.

Conclusion

In conclusion, the discovery of CVE-2022-41086 reveals a Windows Group Policy elevation of privilege vulnerability distinct from the previously disclosed CVE-2022-37992. This vulnerability could have severe consequences if exploited by ill-intended actors. It highlights the importance of staying informed about and promptly applying security patches to protect your organization from potential threats.

Timeline

Published on: 11/09/2022 22:15:00 UTC
Last modified on: 11/10/2022 00:33:00 UTC