CVE-2024-31208

MEDIUM6.5EPSS 4.2%

Synapse V2 state resolution weakness allows Denial of Service (DoS)

Published: 4/23/2024Modified: 5/3/2024
Also known as:GHSA-3h7q-rfh9-xm4vPYSEC-2024-50

Description

### Impact A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in how the auth chain cover index is calculated. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. ### Patches Server administrators should upgrade to 1.105.1 or later. ### Workarounds One can: - ban the malicious users or ACL block servers from the rooms; and/or - leave the room and purge the room using the admin API ### For more information If you have any questions or comments about this advisory, please email us at [security AT element.io](mailto:[email protected]).

Affected packages (3)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1MEDIUM6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References (10)