Skip to content

Invisible eavesdropping in group calls

Moderate
dkasak published GHSA-6g67-q39g-r79q Apr 13, 2023

Package

npm matrix-js-sdk (npm)

Affected versions

< 24.1.0

Patched versions

24.1.0

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.

Patches

This is fixed in matrix-js-sdk 24.1.0.

Workarounds

Users may hold group calls in private rooms where only the exact users who are expected to participate in the call are present.

References

None applicable.

For more information

If you have any questions or comments about this advisory please email us at security at matrix.org.

Severity

Moderate
5.0
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

CVE ID

CVE-2023-29529

Weaknesses