tcpdump libpcap up to 1.10.5 on Windows Error Message utf_16le_to_utf_8_truncated out-of-bounds write

Summaryinfo

A vulnerability was found in tcpdump libpcap up to 1.10.5 on Windows. It has been rated as critical. The impacted element is the function utf_16le_to_utf_8_truncated of the component Error Message Handler. This manipulation causes out-of-bounds write. This vulnerability is registered as CVE-2025-11964. The attack needs to be launched locally. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in tcpdump libpcap up to 1.10.5 on Windows and classified as problematic. Affected by this vulnerability is the function utf_16le_to_utf_8_truncated of the component Error Message Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

On Windows only, if libpcap needs to convert a Windows error message to UTF-8 and the message includes characters that UTF-8 represents using 4 bytes, utf_16le_to_utf_8_truncated() can write data beyond the end of the provided buffer.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2025-11964 since 10/20/2025. The exploitation appears to be difficult. Attacking locally is a requirement. The exploitation requires an enhanced level of successful authentication. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 281674 (Linux Distros Unpatched Vulnerability : CVE-2025-11964), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.10.6 eliminates this vulnerability. Applying the patch 7fabf607f2319a36a0bd78444247180acb838e69 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 vulnerability database at Tenable (281674). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Packet Analyzer Software

Vendor

• tcpdump

Name

• libpcap

Version

• 1.10.0
• 1.10.1
• 1.10.2
• 1.10.3
• 1.10.4
• 1.10.5

License

• open-source

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