FreeRDP up to 3.19.x on Windows Remote Desktop Protocol freerdp_certificate_data_hash Hostname out-of-bounds

Summaryinfo

A vulnerability has been found in FreeRDP up to 3.19.x on Windows and classified as problematic. Affected by this vulnerability is the function freerdp_certificate_data_hash of the component Remote Desktop Protocol. Performing a manipulation of the argument Hostname results in out-of-bounds. This vulnerability is known as CVE-2025-68118. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in FreeRDP up to 3.19.x on Windows. This affects the function freerdp_certificate_data_hash of the component Remote Desktop Protocol. The manipulation of the argument hostname with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, and availability. The summary by CVE is:

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.20.0, a vulnerability exists in FreeRDP’s certificate handling code on Windows platforms. The function `freerdp_certificate_data_hash_ uses` the Microsoft-specific `_snprintf` function to format certificate cache filenames without guaranteeing NUL termination when truncation occurs. According to Microsoft documentation, `_snprintf` does not append a terminating NUL byte if the formatted output exceeds the destination buffer size. If an attacker controls the hostname value (for example via server redirection or a crafted .rdp file), the resulting filename buffer may not be NUL-terminated. Subsequent string operations performed on this buffer may read beyond the allocated memory region, resulting in a heap-based out-of-bounds read. In default configurations, the connection is typically terminated before sensitive data can be meaningfully exposed, but unintended memory read or a client crash may still occur under certain conditions. Version 3.20.0 has a patch for the issue.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2025-68118 since 12/15/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 279429 (Linux Distros Unpatched Vulnerability : CVE-2025-68118), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.20.0 eliminates this vulnerability. Applying the patch a0b21f992a9de1de2468fc9e600aa2b7a4066307 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (279429) and CERT Bund (WID-SEC-2025-2877). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Open Source FreeRDP

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

License

• open-source

Website

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

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Be aware that VulDB is the high quality source for vulnerability data.

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