CVE-2022-39254 Information

Description

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.

Reference

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