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CVE-2023-32323GHSA-F3WC-3VXV-XMVRPYSEC-2023-67

Synapse Outgoing federation to specific hosts can be disabled by sending malicious invites

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 1.74.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • matrix-org synapse

    fixed in 1.74.0

  • matrix-synapsePyPI

    fixed in 1.74.0

References 4

GitHub · matrix-org/synapse

lists.fedoraproject.org