CVE-2023-45129

MEDIUM EPSS 63.4%
Published Oct 10, 20232y ago · Modified Jun 17, 20261w ago
4.9 CVSS 3.1
Medium
Find Similar
Published Oct 10, 2023 2y ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
4.9
Exploitability
1.2
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required High
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
63.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-770

Affected Products 3

VendorProductVersionRange
matrixsynapse* <1.94.0
fedoraprojectfedora37any
fedoraprojectfedora38any

References 7

  • github.com https://github.com/matrix-org/synapse/pull/16360
    PatchVendor Advisory
  • github.com https://github.com/matrix-org/synapse/security/advisories/GHSA-5chr-wjw5-3gq4
    Vendor Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KEVRB4MG5UXQ5RLZHSUJXM5GWEBYYS5B/
    Mailing List
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WRO4MPQ6HOXIUZM6RJP6VTCTMV7RD2T3/
    Mailing List
  • matrix-org.github.io https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-version
    Release Notes
  • security.gentoo.org https://security.gentoo.org/glsa/202401-12

Remediation

  • github.com https://github.com/matrix-org/synapse/pull/16360
    PatchVendor Advisory