CVE-2023-42453 LOW

CVE-2023-42453: Improper validation of receipts allows forged read receipts in matrix synapse

Vendor Matrix-Org
Product synapse
Weakness CWE-285
Published September 26, 2023
Last update June 18, 2025
View on NVD All CVEs

CVSS base score

3.1/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

September 26, 2023 CVE published
June 18, 2025 Record updated

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