CVE-2021-29430

 

Published at: - 15-04-2021 11:15

Last modified: - 03-08-2022 12:13

Total changes: - 3

Description

Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

 

Verification logic

 

Reference

• https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7
• https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d
• https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428
• https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9
• https://pypi.org/project/matrix-sydent/
• https://github.com/matrix-org/sydent/releases/tag/v2.3.0

 

Keywords

NVD

 

CVE-2021-29430

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures