CVE-2023-45129 MEDIUM

CVE-2023-45129: matrix-synapse vulnerable to denial of service due to malicious server ACL events

Vendor Matrix-Org
Product synapse
Weakness CWE-770 · Uncontrolled resource consumption
Published October 10, 2023
Last update February 13, 2025
View on NVD All CVEs

CVSS base score

4.9/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Prior to version 1.94.0, a malicious server ACL event can impact performance temporarily or permanently leading to a persistent denial of service. Homeservers running on a closed federation (which presumably do not need to use server ACLs) are not affected. Server administrators are advised to upgrade to Synapse 1.94.0 or later. As a workaround, rooms with malicious server ACL events can be purged and blocked using the admin API.

Key dates

02Disclosure timeline

October 10, 2023 CVE published
February 13, 2025 Record updated