CVE-2022-21716: Twisted SSH client and server deny of service during SSH handshake.

CVE-2022-21716 · Severity: low · CVSS 3.1 · Published 2022-03-03

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.

Technologies: twisted (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2022-21716 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2022-21716 being exploited in the wild.
How severe is CVE-2022-21716?
Low severity, with a CVSS score of 3.1, published 3 March 2022.
Which products and versions are affected?
twisted (PyPI) ECOSYSTEM:introduced=21.7.0,fixed=22.2.0, GIT:introduced=0,fixed=89c395ee794e85a9657b112c4351417850330ef9|ECOSYSTEM:introduced=21.7.0,fixed=22.2.0.
Is there a fix for CVE-2022-21716?
Yes. twisted (PyPI): upgrade to 22.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2022-21716?
Check whether you run twisted (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

  • twisted (PyPI): upgrade to 22.2.0 or later
    pip install "twisted>=22.2.0"

Affected products

  • twisted (PyPI) ECOSYSTEM:introduced=21.7.0,fixed=22.2.0, GIT:introduced=0,fixed=89c395ee794e85a9657b112c4351417850330ef9|ECOSYSTEM:introduced=21.7.0,fixed=22.2.0

Identifiers

  • CVE-2022-21716
  • GHSA-rv6r-3f5q-9rgx
  • PYSEC-2022-160

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