CVE-2021-29430: Uncontrolled Resource Consumption
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 a1, 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.
References
- github.com/advisories/GHSA-wmg4-8cp2-hpg9
- github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7
- github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d
- github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428
- github.com/matrix-org/sydent/releases/tag/v2.3.0
- github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9
- nvd.nist.gov/vuln/detail/CVE-2021-29430
- pypi.org/project/matrix-sydent/
Detect and mitigate CVE-2021-29430 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →