Auth bypass in Matrix-Nio Project
CVE-2022-39254
matrix-nio is a Python Matrix client library, designed according to sans I/O principles. Prior to version 0.20, when a users requests a room key from their devices, the software correctly remember the request. Once they receive a forwarded room key, they accept it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.20 fixes the issue.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.007 (49.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.001
Affected products
- Matrix-Nio Project
- Poljar Matrix-Nio — versions < 0.20
Weakness classification (CWE)
References
- github.com/poljar/matrix-nio/security/advisories/GHSA-w4pr-4vjg-hffh (Third Party Advisory)
- github.com/poljar/matrix-nio/commit/b1cbf234a831daa160673defd596e6450e9c29f0 (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2022-39254?
- CVE-2022-39254 is a high-severity vulnerability in Matrix-Nio Project, classified under Improper Authentication. CVSS score: 8.6/10. Published 2022-09-29.
- How severe is CVE-2022-39254?
- High severity. CVSS v3 base score is 8.6 out of 10.