CVE-2022-39200 HIGH

CVE-2022-39200: Signature checks not applied to some retrieved missing events

Vendor Matrix-Org
Product dendrite
Weakness CWE-347
Published September 12, 2022
Last update April 23, 2025

CVSS base score

7.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

Dendrite is a Matrix homeserver written in Go. In affected versions events retrieved from a remote homeserver using the `/get_missing_events` path did not have their signatures verified correctly. This could potentially allow a remote homeserver to provide invalid/modified events to Dendrite via this endpoint. Note that this does not apply to events retrieved through other endpoints (e.g. `/event`, `/state`) as they have been correctly verified. Homeservers that have federation disabled are not vulnerable. The problem has been fixed in Dendrite 0.9.8. Users are advised to upgrade. There are no known workarounds for this issue.

Key dates

02Disclosure timeline

September 12, 2022 CVE published
April 23, 2025 Record updated