Skip to content
Fencer Vulns
high 7.5

CVE-2022-21716 json

Buffer Overflow in Twisted

published 2022-03-03 4 y ago modified 2026-06-17 4 mo ago also GHSA-rv6r-3f5q-9rgx , PYSEC-2022-160 , EUVD-2022-0344

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.5%
EPSS 3.5% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi twisted 22.2.0
  • twisted twisted 22.2.0
  • twisted Debian 14, Debian 13, Debian 12 22.2.0-1

debian advisories DEBIAN-CVE-2022-21716

  • twisted Ubuntu 18.04 LTS 17.9.0-2ubuntu0.3
  • twisted Ubuntu 20.04 LTS 18.9.0-11ubuntu0.20.04.2
  • twisted Ubuntu 22.04 LTS 22.1.0-2ubuntu2.1
  • twisted Ubuntu Pro 14.04 LTS 13.2.0-1ubuntu1.2+esm2
  • twisted Ubuntu Pro 16.04 LTS 16.0.0-1ubuntu0.4+esm1

ubuntu advisories UBUNTU-CVE-2022-21716

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-twisted openstack 16.2, openstack 16.1 16.4.1-19.el8ost
  • python3-twisted openstack 16.2, openstack 16.1 16.4.1-19.el8ost

red hat advisories RHSA-2022:0982RHSA-2022:0992

  • python-Twisted SLE Module for Server Applications 15 SP4, openSUSE Leap 15.4 22.2.0-150400.5.4.1
  • python-Twisted SLE Module for Web and Scripting 12, OpenStack Cloud Crowbar 9, OpenStack Cloud Crowbar 8 +3 more 15.2.1-9.17.1
  • python-Twisted SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +10 more 19.10.0-150200.3.12.1

suse advisories SUSE-SU-2022:2297-1SUSE-SU-2022:2117-1SUSE-SU-2022:2070-1

  • python-Twisted openSUSE Tumbleweed 22.2.0-1.1

opensuse advisories openSUSE-SU-2024:11978-1

  • py3-twisted Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 22.2.0-r0

alpine advisories ALPINE-CVE-2022-21716

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-21716 updated cvss 7.5

python-twisted: SSH client and server denial of service during SSH handshake

  • Red Hat Ansible Automation Platform 2 automation-controller
    affected: no fix available
  • Red Hat Enterprise Linux 6 python-twisted, python-twisted-conch
    affected: no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 13 (Queens) python-twisted Red Hat Satellite 6 python-twisted, python2-twisted Red Hat Service Telemetry Framework 1.3 for RHEL 8 python-twisted
    affected: no fix available
  • Red Hat OpenStack Platform 16.1 python-twisted 16.4.1-19.el8ost, python3-twisted 16.4.1-19.el8ost
    fixed: vendor fix RHSA-2022:0982
  • Red Hat OpenStack Platform 16.2 python-twisted 16.4.1-19.el8ost, python3-twisted 16.4.1-19.el8ost
    fixed: vendor fix RHSA-2022:0992

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

3.51% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/twisted/twisted/security/advisories/GHSA-rv6r-3f5q-9rgx referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi twisted
>=21.7.0, <22.2.0
22.2.0

Affected products

  • twisted twisted

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.