GHSA-9jhm-8m8c-c3f4

GitHub Security Advisory

SSRF in Sydent due to missing validation of hostnames

✓ GitHub Reviewed MODERATE Has CVE

### 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].

PyPI matrix-sydent

Affected versions: 0 (fixed in 2.3.0)

CVE-2021-29431

GHSA ID

GHSA-9jhm-8m8c-c3f4

Published

April 19, 2021 2:54 PM

Last Modified

September 30, 2024 8:40 PM

CVSS Score

5.0 /10

Primary Ecosystem

PyPI

Primary Package

matrix-sydent

GitHub Reviewed

✓ Yes

Last updated: September 16, 2025 6:29 AM

Data from GitHub Advisory Database. This information is provided for research and educational purposes.