CVE-2022-39203: matrix-org matrix-appservice-irc Improper Privilege Management

Vulnerability summary

CVE-2022-39203 is a high (CVSS 8.8) Improper Privilege Management vulnerability in matrix-org matrix-appservice-irc. EPSS estimates a 0.86% chance of exploitation in the next 30 days, higher than 57.9% of scored vulnerabilities.

Timeline

1. 13-09-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

Description

matrix-appservice-irc is an open source Node.js IRC bridge for Matrix. 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 vulnerability has been patched in matrix-appservice-irc 0.35.0. As a workaround operators may 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.

• CWE-269Improper Privilege ManagementThe product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.