CVE-2024-37303: element-hq synapse

Vulnerability summary

CVE-2024-37303 is a medium (CVSS 5.3) vulnerability in element-hq synapse. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.8% of scored vulnerabilities.

Timeline

1. 03-12-2024
   PublishedVulnerability first disclosed.
2. 03-12-2024
   Last modifiedVulnerability information updated.

Description

Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.

• CWE-306Missing Authentication for Critical FunctionThe product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.