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.
Advisories
Source ID Title
EUVD EUVD EUVD-2021-0119 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.
Github GHSA Github GHSA GHSA-wmg4-8cp2-hpg9 Sydent vulnerable to denial of service attack via memory exhaustion
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2024-08-03T22:02:51.883Z

Reserved: 2021-03-30T00:00:00

Link: CVE-2021-29430

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-04-15T21:15:17.413

Modified: 2024-11-21T06:01:04.847

Link: CVE-2021-29430

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.