Summary
Parsing issue in matrix-org/node-irc leading to room takeovers
Patched
The vulnerability has been patched in matrix-appservice-irc 0.35.0.
Workarounds
Disable dynamic channel joining via dynamicChannels.enabled to prevent users from joining new channels, which prevents any new channels being bridged outside of what is already bridged, and what is specified in the config.
References
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].
Impact
Attackers can specify a specific string of characters, which would confuse the bridge into combining an attacker-owned channel and an existing channel, allowing them to grant themselves permissions in the channel.
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-2022-39203 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. 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.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2022-39203? CVE-2022-39203 is a high-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.
- How severe is CVE-2022-39203? CVE-2022-39203 has a CVSS score of 8.8 (High). 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.
- Which versions of matrix-appservice-irc are affected by CVE-2022-39203? matrix-appservice-irc (npm) versions < 0.35.0 is affected.
- Is there a fix for CVE-2022-39203? Yes. CVE-2022-39203 is fixed in 0.35.0. Upgrade to this version or later.
- Is CVE-2022-39203 exploitable, and should I be worried? Whether CVE-2022-39203 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
- What actually determines whether CVE-2022-39203 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.
- How do I fix CVE-2022-39203? Upgrade
matrix-appservice-ircto 0.35.0 or later.