Vulnerability Monitor

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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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.7, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 1 product from matrix organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-04-15T21:15:17.520

Last Modified

2024-11-21T06:01:04.993

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.7 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:S/C:P/I:N/A:N

Access Vector: NETWORK
Access Complexity: LOW
Authentication: SINGLE
Confidentiality Impact: PARTIAL
Integrity Impact: NONE
Availability Impact: NONE

Exploitability Score

8.0

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-20
CWE-918

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	matrix	sydent	< 2.3.0	Yes

References

https://github.com/matrix-org/sydent/commit/0f00412017f25619bc36c264b29ea96808bf310a Patch, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/commit/3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3 Patch, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/commit/8936925f561b0c352c2fa922d5097d7245aad00a Patch, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/commit/9e573348d81df8191bbe8c266c01999c9d57cd5f Patch, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/releases/tag/v2.3.0 Release Notes, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/security/advisories/GHSA-9jhm-8m8c-c3f4 Patch, Third Party Advisory ([email protected])
https://pypi.org/project/matrix-sydent/ Product, Third Party Advisory ([email protected])
https://github.com/matrix-org/sydent/commit/0f00412017f25619bc36c264b29ea96808bf310a Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/matrix-org/sydent/commit/3d531ed50d2fd41ac387f36d44d3fb2c62dd22d3 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/matrix-org/sydent/commit/8936925f561b0c352c2fa922d5097d7245aad00a Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/matrix-org/sydent/commit/9e573348d81df8191bbe8c266c01999c9d57cd5f Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/matrix-org/sydent/releases/tag/v2.3.0 Release Notes, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/matrix-org/sydent/security/advisories/GHSA-9jhm-8m8c-c3f4 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://pypi.org/project/matrix-sydent/ Product, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For matrix's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.