CVE-2024-53867
Synapse Matrix has a partial room state leak via Sliding Sync
Description
### Impact The Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected. ### Patches Synapse version 1.120.1 fixes the problem. ### Workarounds Disable Sliding Sync. ### References https://github.com/matrix-org/matrix-spec-proposals/pull/4186 https://github.com/element-hq/synapse/blob/d80cd57c54427687afcb48740d99219c88a0fff1/synapse/config/experimental.py#L341-L344 ### For more information If you have any questions or comments about this advisory, please email us at [security at element.io](mailto:[email protected]).
How to fix CVE-2024-53867
To remediate CVE-2024-53867, upgrade the affected package to a fixed version below.
- —upgrade to 1.121.0-1 or later
- —upgrade to 1.120.1 or later
Is CVE-2024-53867 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 1.121.0-1
- >= 1.113.0rc1, < 1.120.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N |