CVE-2024-37303

Publication date 3 December 2024

Last updated 8 April 2025

Ubuntu priority

Medium

Why this priority?

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
matrix-synapse 24.10 oracular
Vulnerable, fix deferred
24.04 LTS noble
Vulnerable, fix deferred
22.04 LTS jammy
Vulnerable, fix deferred
20.04 LTS focal
Vulnerable, fix deferred
18.04 LTS bionic
Vulnerable, fix deferred

Notes

john-breton

The linked PR is a specification change and does not include code changes as of 7/4/2025. May be possible to extract the fix from the 1.106.0-1 source, but unlikely.