CVE-2021-29431
HIGH7.7EPSS 0.30%SSRF in Sydent due to missing validation of hostnames
Published: 4/19/2021Modified: 3/13/2026
Description
### Impact 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. ### Patches Fixed in 9e57334, 8936925, 3d531ed, 0f00412 ### Workarounds A potential workaround would be to use a firewall to ensure that Sydent cannot reach internal HTTP resources. ### For more information If you have any questions or comments about this advisory, email us at [email protected].
Affected packages (2)
- PyPI/matrix-sydentfrom 0, < 2.3.0
- PyPI/matrix-sydentfrom 0, < 3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3, < 0f00412017f25619bc36c264b29ea96808bf310a, < 9e573348d81df8191bbe8c266c01999c9d57cd5f, < 8936925f561b0c352c2fa922d5097d7245aad00a | from 0, < 2.3.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N |
| osv | CVSS 3.1 | HIGH7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2021-29431
- PATCHhttps://github.com/matrix-org/sydent
- PATCHhttps://pypi.org/project/matrix-sydent/
- WEBhttps://github.com/matrix-org/sydent/commit/0f00412017f25619bc36c264b29ea96808bf310a
- WEBhttps://github.com/matrix-org/sydent/commit/3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3
- WEBhttps://github.com/matrix-org/sydent/commit/8936925f561b0c352c2fa922d5097d7245aad00a
- WEBhttps://github.com/matrix-org/sydent/commit/9e573348d81df8191bbe8c266c01999c9d57cd5f
- WEBhttps://github.com/matrix-org/sydent/releases/tag/v2.3.0
- WEBhttps://github.com/matrix-org/sydent/security/advisories/GHSA-9jhm-8m8c-c3f4
- WEBhttps://github.com/pypa/advisory-database/tree/main/vulns/matrix-sydent/PYSEC-2021-22.yaml
- WEBhttps://pypi.org/project/matrix-sydent