PT-2023-28988 · Synapse+3 · Synapse+3

Erikjohnston · Published 2023-10-31 · Updated 2025-04-22 · CVE-2023-43796

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Synapse versions prior to 1.95.1 and 1.96.0rc1

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.

Recommendations To resolve the issue, upgrade to Synapse 1.95.1 or 1.96.0rc1 to receive a patch. As a temporary workaround, the federation domain whitelist can be used to limit federation traffic with a homeserver.

Exploit

Fix

Information Disclosure

Weakness Enumeration

CWE-200

Related Identifiers

ALT-PU-2024-3315

CVE-2023-43796

GHSA-MP92-3JFM-3575

OPENSUSE-SU-2024:13392-1

PYSEC-2023-230

USN-7444-1

Affected Products

Alt Linux

Linuxmint

Synapse

Ubuntu

References · 31

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43796.json · Exploit
• https://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575 · Vendor Advisory
• https://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f · Patch
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/VH3RNC5ZPQZ4OKPSL4E6BBJSZOQLGDEY · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2023-43796 · Vendor Advisory
• https://osv.dev/vulnerability/USN-7444-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2023-42453 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2023-43796 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-7444-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2024-53863 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/2IDEEZMFJBDLTFHQUTZRJJNCOZGQ2ZVS · Vendor Advisory
• https://ubuntu.com/security/CVE-2023-32683 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-39335 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2023-43796 · Security Note
• https://ubuntu.com/security/CVE-2023-41335 · Vendor Advisory