Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read. This could be confusing as clients will show the event as read by the user, even if they are not in the room. This issue has been patched in version 1.93.0. Users are advised to upgrade. There are no known workarounds for this issue.
Advisories
Source ID Title
EUVD EUVD EUVD-2023-0133 Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read. This could be confusing as clients will show the event as read by the user, even if they are not in the room. This issue has been patched in version 1.93.0. Users are advised to upgrade. There are no known workarounds for this issue.
Github GHSA Github GHSA GHSA-7565-cq32-vx2x matrix-synapse vulnerable to improper validation of receipts allows forged read receipts
Ubuntu USN Ubuntu USN USN-7444-1 Synapse vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 18 Jun 2025 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 13 Feb 2025 17:15:00 +0000

Type Values Removed Values Added
Title Improper validation of receipts allows forged read receipts in matrix synapse Improper validation of receipts allows forged read receipts in matrix synapse

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-06-18T14:11:32.728Z

Reserved: 2023-09-08T20:57:45.573Z

Link: CVE-2023-42453

cve-icon Vulnrichment

Updated: 2024-08-02T19:23:38.904Z

cve-icon NVD

Status : Modified

Published: 2023-09-27T15:19:32.453

Modified: 2024-11-21T08:22:33.887

Link: CVE-2023-42453

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.