Synapse Outgoing federation to specific hosts can be disabled by sending malicious invites
CVE-2023-32323

4.3MEDIUM

Key Information:

Vendor

Matrix-org

Status
Synapse
Vendor
CVE Published:
26 May 2023

What is CVE-2023-32323?

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 Version(s)

synapse < 1.74.0

References

https://github.com/matrix-org/synapse/security/advisories...
x_refsource_CONFIRM
https://github.com/matrix-org/synapse/issues/14492
x_refsource_MISC
https://github.com/matrix-org/synapse/pull/14642
x_refsource_MISC

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.