[Pkg-matrix-maintainers] Bug#1055255: matrix-synapse: CVE-2023-43796

[Salvatore Bonaccorso]

Source: matrix-synapse
Version: 1.95.0-1
Severity: grave
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for matrix-synapse.

CVE-2023-43796[0]:
| 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2023-43796
    https://www.cve.org/CVERecord?id=CVE-2023-43796
[1] https://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575
[2] https://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f 

Regards,
Salvatore