CVE-2022-39202

matrix-appservice-irc vulnerable to IRC mode parameter confusion

Workarounds

Refrain from entering mode commands suggested by untrusted users. Avoid using multiple modes in a single command.

References

• https://matrix.org/blog/2022/09/13/security-release-of-matrix-appservice-irc-0-35-0-high-severity

Credits

Discovered and reported by Val Lorentz.

For more information

If you have any questions or comments about this advisory email us at [email protected].

IRC allows you to specify multiple modes in a single mode command. Due to a bug in the underlying matrix-org/node-irc library, affected versions of matrix-appservice-irc perform parsing of such modes incorrectly, potentially resulting in the wrong user being given permissions.

Mode commands can only be executed by privileged users, so this can only be abused if an operator is tricked into running the command on behalf of an attacker.

The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access. Typical impact: privilege escalation beyond the intended level.

CVE-2022-39202 has a CVSS score of 4.3 (Medium). The vector is network-reachable, high privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.35.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

The vulnerability has been patched in matrix-appservice-irc 0.35.0.

1. What is CVE-2022-39202? CVE-2022-39202 is a medium-severity improper privilege management vulnerability in matrix-appservice-irc (npm), affecting versions < 0.35.0. It is fixed in 0.35.0. The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access.
2. How severe is CVE-2022-39202? CVE-2022-39202 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of matrix-appservice-irc are affected by CVE-2022-39202? matrix-appservice-irc (npm) versions < 0.35.0 is affected.
4. Is there a fix for CVE-2022-39202? Yes. CVE-2022-39202 is fixed in 0.35.0. Upgrade to this version or later.
5. Is CVE-2022-39202 exploitable, and should I be worried? Whether CVE-2022-39202 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2022-39202 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2022-39202? Upgrade matrix-appservice-irc to 0.35.0 or later.

Other vulnerabilities in matrix-appservice-irc