Privilege escalation in Matrix Irc Bridge

CVE-2022-39203

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.

Vulnerability class: Privilege Escalation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (56.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2022-39203: held from 0.008 to 0.008.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2022-39203?
CVE-2022-39203 is a high-severity vulnerability in Matrix Irc Bridge, classified under Improper Privilege Management. CVSS score: 8.8/10. Published 2022-09-13.
How severe is CVE-2022-39203?
High severity. CVSS v3 base score is 8.8 out of 10.