GHSA-jhjh-776m-4765

Denial of service due to incorrect application of event authorization rules

Source: GitHub Advisory Database (reviewed) High CVE-2022-31152

Packages

Ecosystem	Package	Affected	Fixed in
PyPI	matrix-synapse	< 1.62.0rc1	1.62.0rc1

Details

As written in the advisory (Markdown source, shown as plain text).

### Impact The Matrix specification specifies a list of [event authorization rules](https://spec.matrix.org/v1.3/rooms/v10/#authorization-rules) which must be checked when determining if an event should be accepted into a room. In versions of Synapse up to and including v1.61, some of these rules are not correctly applied. An attacker could craft events which would be accepted by Synapse but not a spec-conformant server, potentially causing divergence in the room state between servers. ### Patches Administrators of homeservers with federation enabled are advised to upgrade to v1.62.0 or higher. ### Workarounds * Federation can be disabled by setting [`federation_domain_whitelist`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#federation_domain_whitelist) to an empty list (`[]`). ### References * https://github.com/matrix-org/synapse/pull/13087 * https://github.com/matrix-org/synapse/pull/13088 ### For more information If you have any questions or comments about this advisory, e-mail us at [[email protected]](mailto:[email protected]).

References

External links from the advisory. They lead to third-party sites.