Executive Summary

CVE-2026-25994 is a buffer overflow vulnerability in the ICE (Interactive Connectivity Establishment) component of the PJNATH library, which is part of the pjsip multimedia communication library. This vulnerability occurs when processing credentials that contain excessively long usernames. Specifically, in versions 2.16 and earlier, the code did not properly validate the length of username fragments and passwords, allowing buffer overflow conditions during ICE session creation.

The vulnerability arises because the combined length of local and remote username fragments could exceed the fixed buffer size, leading to memory corruption. The fix involved increasing the buffer size and adding strict length checks on usernames and passwords to prevent this overflow.

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Impact Analysis

This vulnerability can lead to serious security issues including unexpected application termination, memory corruption, and potential control flow hijacking. An attacker could exploit the buffer overflow by supplying excessively long usernames in ICE credentials, which may allow them to execute arbitrary code or cause the application to crash.

Such impacts pose significant risks to applications that use the ICE component for connectivity, potentially compromising the confidentiality, integrity, and availability of the affected system.

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Compliance Impact

I don't know

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Detection Guidance

[{'type': 'paragraph', 'content': 'This vulnerability involves buffer overflow due to excessively long usernames in ICE credentials processed by the PJNATH library. Detection involves identifying ICE sessions with username fragments exceeding safe length limits.'}, {'type': 'list_item', 'content': 'Check for ICE credentials where the combined length of local and remote username fragments exceeds 512 bytes.'}, {'type': 'list_item', 'content': 'Look for remote username fragments shorter than 4 bytes or remote passwords shorter than 22 bytes, which are considered invalid.'}, {'type': 'paragraph', 'content': 'Since the vulnerability is related to PJNATH ICE session credential processing, monitoring logs for messages at log level 5 (LOG5) indicating failures such as "The ufrag must be at least 4 bytes, passwd at least 22 bytes" or "Combined usernames must not exceed 512 bytes" can help detect attempts to exploit this issue.'}, {'type': 'paragraph', 'content': 'Specific commands depend on your environment, but you can use network traffic inspection tools (e.g., Wireshark) to capture ICE credential exchanges and scripts or tools to parse and measure username fragment lengths in SIP or ICE messages.'}] [1]

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Mitigation Strategies

The primary mitigation is to upgrade the pjnath library to version 2.17 or later, where the vulnerability has been fixed.

The fix includes enhanced validation of ICE credentials, enforcing minimum lengths for username fragments and passwords, and limiting the combined username length to 512 bytes to prevent buffer overflow.

If upgrading immediately is not possible, consider implementing network-level filtering to block or limit ICE credentials with suspiciously long usernames or invalid credential lengths.

Monitor application logs for the specific error messages introduced in the patch to detect and respond to potential exploit attempts.

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