CVE-2024-31208

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

23/04/2024

Last modified:

26/08/2025

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

6.50

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:matrix:synapse::::::::		1.105.1 (excluding)
cpe:2.3:o:fedoraproject:fedora:38:::::::*
cpe:2.3:o:fedoraproject:fedora:39:::::::*
cpe:2.3:o:fedoraproject:fedora:40:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2024-31208

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools