CVE-2021-29431

SSRF in Sydent due to missing validation of hostnames

Published Apr 15, 2021 CVSS 3.1 · 7.7 High EPSS 1.2% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2021-0120 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.
Github GHSA Github GHSA GHSA-9jhm-8m8c-c3f4 SSRF in Sydent due to missing validation of hostnames
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 3, 2024, 10:02 PM
Reserved
Mar 30, 2021, 12:00 AM
Status
Modified
Published
Apr 15, 2021, 9:15 PM
Modified
Jun 17, 2026, 3:47 AM