CVE-2022-39335 Synapse does not apply enough checks to servers requesting auth events of events in a room
Remote servers can improperly access authorization events in a room due to insufficient checks, potentially exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-39335?
CVE-2022-39335 is a medium-severity missing authorization vulnerability in matrix-org synapse, published on 26 May 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix Federation API allows remote homeservers to request the authorization events in a room. This is necessary so that a homeserver receiving some events can validate that those events are legitimate and permitted in their room. However, in versions of Synapse up to and including 1.68.0, a Synapse homeserver answering a query for authorization events does not sufficiently check that the requesting server should be able to access them. The issue was patched in Synapse 1.69.0. Homeserver administrators are advised to upgrade.
Which versions are affected by CVE-2022-39335?
3 open source packages ship an affected version, including matrix-synapse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
matrix-synapse PyPI | All versions | 1.69.0 |
matrix-synapse PyPI | All versions | 1.69.0 |
matrix-synapse PyPI | All versions | 1.69.0 |
Products include Matrix Synapse.
How do I fix CVE-2022-39335?
Upgrade matrix-synapse to 1.69.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2022-39335 being exploited?
There is no known exploitation of CVE-2022-39335 in the wild and no public exploit code.
Other vulnerabilities in matrix-org synapse
- CVE-2019-18835 Improper Verification of Cryptographic Signature in matrix-synapse
- CVE-2024-52815 Synapse allows a a malformed invite to break the invitee's `/sync`
- CVE-2024-52805 Synapse allows unsupported content types to lead to memory exhaustion
- CVE-2024-53863 Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders
- CVE-2024-37302 Synapse denial of service through media disk space consumption
Sources
Also known as GHSA-45cj-f97f-ggwv, PYSEC-2023-65, UBUNTU-CVE-2022-39335.