Headline
GHSA-jhjh-776m-4765: Denial of service due to incorrect application of event authorization rules
Impact
The Matrix specification specifies a list of event 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_whitelistto 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].
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2022-31152
Denial of service due to incorrect application of event authorization rules
Moderate severity GitHub Reviewed Published Aug 31, 2022 in matrix-org/synapse • Updated Aug 31, 2022
Vulnerability details Dependabot alerts 0
Package
pip matrix-synapse (pip)
Affected versions
< 1.62
Patched versions
1.62
Description
Impact
The Matrix specification specifies a list of event 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 to an empty list ([]).
References
- matrix-org/synapse#13087
- matrix-org/synapse#13088
For more information
If you have any questions or comments about this advisory, e-mail us at [email protected].
References
- GHSA-jhjh-776m-4765
- matrix-org/synapse#13087
- matrix-org/synapse#13088
- https://github.com/matrix-org/synapse/releases/tag/v1.62.0
richvdh published the maintainer security advisory
Aug 31, 2022
Severity
Moderate
Weaknesses
No CWEs
CVE ID
CVE-2022-31152
GHSA ID
GHSA-jhjh-776m-4765
Source code
matrix-org/synapse
Checking history
See something to contribute? Suggest improvements for this vulnerability.
Related news
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.