Vulnerability advisory
GHSA-6g67-q39g-r79q
matrix-js-sdk vulnerable to invisible eavesdropping in group calls
Also known as CVE-2023-29529
- CVSS 3.x
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Affected versions
| Affected | Fixed in |
|---|---|
| All versions before 24.1.0 | 24.1.0Advisories → |
Description
Impact
An attacker present in a room where an MSC3401 group call is taking place can eavesdrop on the video and audio of participants using matrix-js-sdk, without their knowledge. To affected matrix-js-sdk users, the attacker will not appear to be participating in the call.
This attack is possible because matrix-js-sdk's group call implementation accepts incoming direct calls from other users, even if they have not yet declared intent to participate in the group call, as a means of resolving a race condition in call setup. Affected versions do not restrict access to the user's outbound media in this case.
Legacy 1:1 calls are unaffected.
Workarounds
Users may hold group calls in private rooms where only the exact users who are expected to participate in the call are present.