CVE-2023-43796
MEDIUM5.3EPSS 0.28%Synapse vulnerable to leak of remote user device information
Published: 10/31/2023Modified: 5/20/2026
Description
Synapse is an open-source Matrix homeserver Prior to versions 1.95.1 and 1.96.0rc1, cached device information of remote users can be queried from Synapse. This can be used to enumerate the remote users known to a homeserver. System administrators are encouraged to upgrade to Synapse 1.95.1 or 1.96.0rc1 to receive a patch. As a workaround, the `federation_domain_whitelist` can be used to limit federation traffic with a homeserver.
Affected packages (3)
- Debian/matrix-synapsefrom 0, < 1.95.1-1
- PyPI/matrix-synapsefrom 0, < 1.95.1
- PyPI/matrix-synapsefrom 0, < daec55e1fe120c564240c5386e77941372bf458f | from 0, < 1.95.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
References (9)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2023-43796
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2023-43796
- PATCHhttps://github.com/matrix-org/synapse
- WEBhttps://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f
- WEBhttps://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575
- WEBhttps://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-230.yaml
- WEBhttps://lists.fedoraproject.org/archives/list/[email protected]/message/2IDEEZMFJBDLTFHQUTZRJJNCOZGQ2ZVS
- WEBhttps://lists.fedoraproject.org/archives/list/[email protected]/message/VH3RNC5ZPQZ4OKPSL4E6BBJSZOQLGDEY
- WEBhttps://security.gentoo.org/glsa/202401-12