CVE-2021-29431
Description
Sydent is a reference Matrix identity server. Sydent can be induced to send HTTP GET requests to internal systems, due to lack of parameter validation or IP address blacklisting. It is not possible to exfiltrate data or control request headers, but it might be possible to use the attack to perform an internal port enumeration. This issue has been addressed in in 9e57334, 8936925, 3d531ed, 0f00412. A potential workaround would be to use a firewall to ensure that Sydent cannot reach internal HTTP resources.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | matrix-sydent | <2.3.0 | 2.3.0 |
| PyPI | matrix-sydent | <8936925f561b0c352c2fa922d5097d7245aad00a||<2.3.0 | 3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3 |
References
- https://github.com/matrix-org/sydent/security/advisories/GHSA-9jhm-8m8c-c3f4
- https://nvd.nist.gov/vuln/detail/CVE-2021-29431
- https://github.com/matrix-org/sydent/commit/0f00412017f25619bc36c264b29ea96808bf310a
- https://github.com/matrix-org/sydent/commit/3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3
- https://github.com/matrix-org/sydent/commit/8936925f561b0c352c2fa922d5097d7245aad00a
- https://github.com/matrix-org/sydent/commit/9e573348d81df8191bbe8c266c01999c9d57cd5f
- https://github.com/matrix-org/sydent
- https://github.com/matrix-org/sydent/releases/tag/v2.3.0
- https://github.com/pypa/advisory-database/tree/main/vulns/matrix-sydent/PYSEC-2021-22.yaml
- https://pypi.org/project/matrix-sydent
- https://pypi.org/project/matrix-sydent/
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.