vulnerability
Red Hat: CVE-2022-21716: python-twisted: SSH client and server denial of service during SSH handshake
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:N/I:N/A:P) | Mar 3, 2022 | Jul 9, 2025 | Jul 9, 2025 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:P)
Published
Mar 3, 2022
Added
Jul 9, 2025
Modified
Jul 9, 2025
Description
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.
Solution
no-fix-redhat-rpm-package
References
Rapid7 Labs
2026 Global Threat Landscape Report
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