CVE-2022-39335: Synapse does not apply enough checks to servers requesting auth events of events in a room

CVE-2022-39335 · Severity: low · CVSS 3.1 · Published 2023-05-26

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.

Technologies: matrix-synapse (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2022-39335 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2022-39335 being exploited in the wild.
How severe is CVE-2022-39335?
Low severity, with a CVSS score of 3.1, published 26 May 2023.
Which products and versions are affected?
matrix-synapse (PyPI) ECOSYSTEM:introduced=0,fixed=1.69.0.
Is there a fix for CVE-2022-39335?
Yes. matrix-synapse (PyPI): upgrade to 1.69.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2022-39335?
Check whether you run matrix-synapse (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • matrix-synapse (PyPI): upgrade to 1.69.0 or later
    pip install "matrix-synapse>=1.69.0"

Affected products

  • matrix-synapse (PyPI) ECOSYSTEM:introduced=0,fixed=1.69.0

Identifiers

  • CVE-2022-39335
  • GHSA-45cj-f97f-ggwv
  • PYSEC-2023-65

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