Headline
GHSA-mp92-3jfm-3575: Synapse vulnerable to leak of remote user device information
Impact
Cached device information of remote users can be queried from Synapse. This can be used to enumerate the remote users known to a homeserver.
Patches
System administrators are encouraged to upgrade to Synapse 1.95.1 as soon as possible.
Workarounds
The federation_domain_whitelist can be used to limit federation traffic with a homeserver.
Synapse vulnerable to leak of remote user device information
Moderate severity GitHub Reviewed Published Oct 31, 2023 in matrix-org/synapse • Updated Oct 31, 2023
Related news
Gentoo Linux Security Advisory 202401-12 - Multiple vulnerabilities have been found in Synapse, the worst of which could result in information leaks. Versions greater than or equal to 1.96.0 are affected.
Synapse is an open-source Matrix homeserver Prior to versions 1.95.1 and 1.96.0rc1, cached device information of remote users can be queried from Synapse. This can be used to enumerate the remote users known to a homeserver. System administrators are encouraged to upgrade to Synapse 1.95.1 or 1.96.0rc1 to receive a patch. As a workaround, the `federation_domain_whitelist` can be used to limit federation traffic with a homeserver.