CVE-2023-45129: matrix-synapse vulnerable to denial of service due to malicious server ACL events
Impact 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.
Patches Server administrators are advised to upgrade to Synapse 1.94.0 or later.
Workarounds Rooms with malicious server ACL events can be purged and blocked using the admin API.
Other sources
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.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2023-45129?
CVE-2023-45129 is a vulnerability in Synapse, an open-source Matrix homeserver, that can lead to a persistent denial of service due to a malicious server ACL event.
What is the impact of CVE-2023-45129?
CVE-2023-45129 can temporarily or permanently impact the performance of the server, resulting in a persistent denial of service.
How does CVE-2023-45129 affect homeservers running on a closed federation?
Homeservers running on a closed federation, that do not need to use server ACLs, are not affected by CVE-2023-45129.
What is the severity of CVE-2023-45129?
CVE-2023-45129 has a severity rating of medium with a CVSS score of 4.9.
How can I fix CVE-2023-45129?
To fix CVE-2023-45129, server administrators are advised to upgrade to version 1.94.0 of matrix-synapse.