CVE-2022-39254

Advisory

Matrix-nio 0.20 includes a fix for CVE-2022-39254: Prior to version 0.20, when a user 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.

Affected package

Affected versions

Fixed versions

Vulnerability changelog

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. See CVE-2022-39254.


CONFIRM:https://github.com/poljar/matrix-nio/security/advisories/GHSA-w4pr-4vjg-hffh: https://github.com/poljar/matrix-nio/security/advisories/GHSA-w4pr-4vjg-hffh
MISC:https://github.com/poljar/matrix-nio/commit/b1cbf234a831daa160673defd596e6450e9c29f0: https://github.com/poljar/matrix-nio/commit/b1cbf234a831daa160673defd596e6450e9c29f0

Resources

• https://github.com/poljar/matrix-nio/security/advisories/GHSA-w4pr-4vjg-hffh
• https://github.com/poljar/matrix-nio/commit/b1cbf234a831daa160673defd596e6450e9c29f0
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-39254