GHSA-p9qp-c452-f9r7

Suggest an improvement
Source
https://github.com/advisories/GHSA-p9qp-c452-f9r7
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/05/GHSA-p9qp-c452-f9r7/GHSA-p9qp-c452-f9r7.json
JSON Data
https://api.test.osv.dev/v1/vulns/GHSA-p9qp-c452-f9r7
Aliases
Published
2023-05-24T17:21:33Z
Modified
2024-09-30T21:34:05.966281Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Synapse Denial of service due to incorrect application of event authorization rules during state resolution
Details

Impact

If Synapse and a malicious homeserver are both joined to the same room, the malicious homeserver can trick Synapse into accepting previously rejected events into its view of the current state of that room. This can be exploited in a way that causes all further messages and state changes sent in that room from the vulnerable homeserver to be rejected.

Synapse homeservers are affected by this issue if and only if they are joined to rooms which members of untrusted homeservers are joined or invited to.

  • Synapse homeservers in rooms available over public federation are affected.
  • Synapse homeservers with federation disabled are not affected.
  • Synapse homeservers in a closed federation containing only trusted servers are not affected.
  • Synapse homeservers which are only joined to rooms with federation disabled[^1] are not affected.

Patches

Administrators of homeservers with federation enabled are advised to upgrade to 1.68.0 or higher.

Workarounds

  • Federation can be disabled by setting federation_domain_whitelist to an empty list ([]). from the vulnerable homeserver to be rejected. This issue has been patched in version 1.68.0

References

  • https://github.com/matrix-org/synapse/pull/13723

For more information

If you have any questions or comments about this advisory, e-mail us at security@matrix.org.

Database specific
{
    "nvd_published_at": "2023-05-26T14:15:10Z",
    "cwe_ids": [
        "CWE-400"
    ],
    "severity": "HIGH",
    "github_reviewed": true,
    "github_reviewed_at": "2023-05-24T17:21:33Z"
}
References

Affected packages

PyPI / matrix-synapse

Package

Affected ranges

Type
ECOSYSTEM
Events
Introduced
1.62.0
Fixed
1.68.0rc1

Affected versions

1.*

1.62.0
1.63.0rc1
1.63.0
1.63.1
1.64.0rc1
1.64.0rc2
1.64.0
1.65.0rc1
1.65.0rc2
1.65.0
1.66.0rc1
1.66.0rc2
1.66.0
1.67.0rc1
1.67.0