{"id":"UBUNTU-CVE-2023-45129","details":"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.","modified":"2025-09-08T16:56:32Z","published":"2023-10-10T18:15:00Z","upstream":["CVE-2023-45129"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-45129"},{"type":"REPORT","url":"https://github.com/matrix-org/synapse/security/advisories/GHSA-5chr-wjw5-3gq4"},{"type":"REPORT","url":"https://github.com/matrix-org/synapse/pull/16360"},{"type":"REPORT","url":"https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-version"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-45129"}],"affected":[{"package":{"name":"matrix-synapse","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/matrix-synapse@0.24.0+dfsg-1ubuntu0.1~esm4?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.19.2+dfsg-6","0.24.0+dfsg-1","0.24.0+dfsg-1ubuntu0.1~esm1","0.24.0+dfsg-1ubuntu0.1~esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"matrix-synapse","binary_version":"0.24.0+dfsg-1ubuntu0.1~esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-45129.json"}},{"package":{"name":"matrix-synapse","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/matrix-synapse@1.11.0-1ubuntu0.1~esm2?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.0-1","1.4.0-1","1.5.0-1","1.5.1-1","1.6.0-1","1.6.1-1","1.7.0-2","1.7.1-1","1.7.2-1","1.7.3-1","1.8.0-1","1.9.0-1","1.9.1-1","1.10.0-1","1.10.0-2","1.11.0-1","1.11.0-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"matrix-synapse","binary_version":"1.11.0-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-45129.json"}},{"package":{"name":"matrix-synapse","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/matrix-synapse@1.53.0-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.39.0-1","1.47.0-2","1.47.1-1","1.48.0-1","1.49.0-1","1.49.2-1","1.50.1-1","1.50.2-1","1.51.0-1","1.52.0-1","1.53.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"matrix-synapse","binary_version":"1.53.0-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-45129.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}