CVE-2022-39200 Signature checks not applied to some retrieved missing events
A remote homeserver can inject invalid or modified events into Dendrite via the get_missing_events endpoint due to missing signature verification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-39200?
CVE-2022-39200 is a high-severity vulnerability in matrix-org dendrite, published on 12 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-347
Which versions are affected by CVE-2022-39200?
3 open source packages ship an affected version, including github.com/matrix-org/dendrite. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/matrix-org/dendrite Go | All versions | 0.9.8 |
github.com/matrix-org/dendrite Go | All versions | 0.9.8 |
github.com/matrix-org/dendrite Go | All versions | 0.9.8 |
Products include Matrix Dendrite.
How do I fix CVE-2022-39200?
Upgrade github.com/matrix-org/dendrite to 0.9.8 or later.
Is CVE-2022-39200 being exploited?
There is no known exploitation of CVE-2022-39200 in the wild and no public exploit code.
Other vulnerabilities in matrix-org dendrite
Sources
Also known as GHSA-pfw4-xjgm-267c, GO-2022-0989.