SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2024-31208

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 the V2 state resolution algorithm.

MEDIUM 6.5EPSS 1.46%

Does this matter?

Lower severity and a low EPSS score (1.46%). Track it; it rarely justifies an emergency change on its own.

Description

Synapse is an open-source Matrix homeserver. 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 the V2 state resolution algorithm. 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. Server administrators should upgrade to 1.105.1 or later. Some workarounds are available. 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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
1.46% probability · 72th percentile
CISA KEV
Not listed
Weakness
CWE-770
Affected
matrix/synapse · fedoraproject/fedora
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.