SSRF in Sydent due to missing validation of hostnames
CVE-2021-29431

7.7HIGH

Key Information:

Vendor

Matrix-org

Status
Sydent
Vendor
CVE Published:
15 April 2021

What is CVE-2021-29431?

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.

Affected Version(s)

sydent < 2.3.0

References

https://pypi.org/project/matrix-sydent/
x_refsource_MISC
https://github.com/matrix-org/sydent/releases/tag/v2.3.0
x_refsource_MISC
https://github.com/matrix-org/sydent/security/advisories/...
x_refsource_CONFIRM

CVSS V3.1

Score:
7.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.