Medium severity · published Oct 31, 2023
CVE-2023-43796
Synapse vulnerable to leak of remote user device information
5.3
CVSS
0.9%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 60% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SY
synapse · matrix-org
< 1.95.1 · source: vendor, NVD
FE
Fedora · Fedoraproject
38; 39 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-43796
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-43796
Patch
https://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f
Vendor Advisory
https://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575
Mailing List
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2IDEEZMFJBDLTFHQUTZRJJNCOZGQ2ZVS/
Mailing List
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VH3RNC5ZPQZ4OKPSL4E6BBJSZOQLGDEY/
security.gentoo.org
https://security.gentoo.org/glsa/202401-12
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