rh#2124168

Synapse is an open-source Matrix homeserver written and maintained by the
Matrix.org Foundation. The Matrix specification specifies a list of [event
authorization
rules](https://spec.matrix.org/v1.2/rooms/v9/#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 version 1.61.0, 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. Administrators of homeservers
with
federation enabled are advised to upgrade to version 1.62.0 or higher.
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 (`[]`) as a workaround.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=2124168
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2022-31152
https://github.com/matrix-org/synapse/pull/13087
https://github.com/matrix-org/synapse/releases/tag/v1.62.0
https://github.com/matrix-org/synapse/security/advisories/GHSA-jhjh-776m-4765
https://github.com/matrix-org/synapse/pull/13088
https://www.cve.org/CVERecord?id=CVE-2022-31152