Microsoft Windows up to Server 2025 Remote Desktop Client path traversal

Summaryinfo

A vulnerability, which was classified as critical, has been found in Microsoft Windows. Affected by this issue is some unknown functionality of the component Remote Desktop Client. This manipulation causes path traversal. This vulnerability is tracked as CVE-2025-26645. The attack is possible to be carried out remotely. No exploit exists. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Windows. Affected by this vulnerability is an unknown functionality of the component Remote Desktop Client. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-23. The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Relative path traversal in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

The weakness was disclosed 03/11/2025 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is known as CVE-2025-26645. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/08/2025). MITRE ATT&CK project uses the attack technique T1006 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 232622 (KB5053887: Windows Server 2012 R2 Security Update (March 2025)), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (232622). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 10
• 10 21H2
• 10 22H2
• 10 1607
• 10 1809
• 11 22H2
• 11 23H2
• 11 24H2
• App Client
• Remote Desktop client
• Server 2008 R2 SP1
• Server 2008 SP2
• Server 2012
• Server 2012 R2
• Server 2016
• Server 2019
• Server 2022
• Server 2022 23H2
• Server 2025

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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