vulnerability
Ubuntu: USN-7444-1 (CVE-2023-43796): Synapse vulnerabilities
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:P/I:N/A:N) | Oct 31, 2023 | Apr 24, 2025 | Mar 27, 2026 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:P/I:N/A:N)
Published
Oct 31, 2023
Added
Apr 24, 2025
Modified
Mar 27, 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.
Solution
ubuntu-pro-upgrade-matrix-synapse
References
- CVE-2023-43796
- https://attackerkb.com/topics/CVE-2023-43796
- CWE-200
- EUVD-EUVD-2023-0136
- UBUNTU-USN-7444-1
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-0136
- https://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f
- https://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575
- https://ubuntu.com/security/notices/USN-7444-1
- https://www.cve.org/CVERecord?id=CVE-2023-43796
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