Vulnerability advisory
GHSA-vhr5-g3pm-49fm
matrix-js-sdk will freeze when a user sets a room with itself as a its predecessor
Also known as CVE-2024-42369
Severity
- CVSS 3.x
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:L - CVSS 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
Affected versions
| Affected | Fixed in |
|---|---|
| All versions before 34.3.1 | 34.3.1Advisories → |
Description
Impact
A malicious homeserver can craft a room or room structure such that the predecessors form a cycle. The matrix-js-sdk's getRoomUpgradeHistory function will infinitely recurse in this case, causing the code to hang. This method is public but also called by the 'leaveRoomChain()' method, so leaving a room will also trigger the bug.
Even if the CVSS score would be 4.1 (AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:L) we classify this as High severity issue.
Patches
This was patched in matrix-js-sdk 34.3.1.
Workarounds
Sanity check rooms before passing them to the matrix-js-sdk or avoid calling either getRoomUpgradeHistory or leaveRoomChain.
References
N/A.