matrix-js-sdk is the Matrix Client-Server SDK for JavaScript and TypeScript. 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. This is fixed in matrix-js-sdk 24.1.0. As a workaround, users may hold group calls in private rooms where only the exact users who are expected to participate in the call are present.
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
| Link | Tags |
|---|---|
| https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-6g67-q39g-r79q | vendor advisory |
| https://github.com/matrix-org/matrix-spec-proposals/pull/3401 | patch issue tracking |
| https://github.com/matrix-org/matrix-js-sdk/releases/tag/v24.1.0 | release notes |