FreeRDP up to 3.24.x Remote Desktop Protocol drive_file.c contains_dotdot off-by-one

Summaryinfo

A vulnerability classified as problematic has been found in FreeRDP up to 3.24.x. This issue affects the function contains_dotdot of the file channels/drive/client/drive_file.c of the component Remote Desktop Protocol. Performing a manipulation results in off-by-one. This vulnerability was named CVE-2026-40254. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in FreeRDP up to 3.24.x. This affects the function contains_dotdot of the file channels/drive/client/drive_file.c of the component Remote Desktop Protocol. The manipulation with an unknown input leads to a off-by-one vulnerability. CWE is classifying the issue as CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

FreeRDP is a free implementation of the Remote Desktop Protocol. Versions prior to 3.25.0 have an off-by-one in the path traversal filter in `channels/drive/client/drive_file.c`. The `contains_dotdot()` function catches `../` and `..\` mid-path but misses `..` when it's the last component with no trailing separator. A rogue RDP server can read, list, or write files one directory above the client's shared folder through RDPDR requests. This requires the victim to connect with drive redirection enabled. Version 3.25.0 patches the issue.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-40254 since 04/10/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 310292 (Linux Distros Unpatched Vulnerability : CVE-2026-40254), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.25.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (310292). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Remote Access Software

Name

• FreeRDP

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.15
• 3.16
• 3.17
• 3.18
• 3.19
• 3.20
• 3.21
• 3.22
• 3.23
• 3.24

License

• open-source

Website

• Product: https://github.com/FreeRDP/FreeRDP/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion