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matrix-org/synapse · Security

Denial of service due to incorrect application of event authorization rules

GHSA ID
GHSA-jhjh-776m-4765
CVE ID
CVE-2022-31152
Severity
high
Published
Updated
CVSS
7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v3
7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4
8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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

References

For more information

If you have any questions or comments about this advisory, e-mail us at [email protected].

CWEs

  • CWE-703 · Improper Check or Handling of Exceptional Conditions
  • CWE-755 · Improper Handling of Exceptional Conditions

References