CVE-2023-32323

Advisory

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. A malicious user on a Synapse homeserver X with permission to create certain state events can disable outbound federation from X to an arbitrary homeserver Y. Synapse instances with federation disabled are not affected. In versions of Synapse up to and including 1.73, Synapse did not limit the size of `invite_room_state`, meaning that it was possible to create an arbitrarily large invite event. Synapse 1.74 refuses to create oversized `invite_room_state` fields. Server operators should upgrade to Synapse 1.74 or newer urgently.

Affected package

Affected versions

Fixed versions

Vulnerability changelog

This vulnerability has no description

Resources

• https://github.com/matrix-org/synapse/security/advisories/GHSA-f3wc-3vxv-xmvr
• https://github.com/matrix-org/synapse/pull/14642
• https://github.com/matrix-org/synapse/issues/14492
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-32323