=========================================================================Ubuntu Security Notice USN-5354-2
May 05, 2022

twisted vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS
- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

Twisted could be made to crash if it received specially crafted network
traffic.

Software Description:
- twisted: Event-based framework for internet applications

Details:

USN-5354-1 fixed vulnerabilities in Twisted. This update provides the
corresponding updates for Ubuntu 14.04 ESM, Ubuntu 16.04 ESM and
Ubuntu 22.04 LTS.

Original advisory details:
  It was discovered that Twisted incorrectly processed SSH handshake data on
  connection establishments. A remote attacker could use this issue to cause
  Twisted to crash, resulting in a denial of service. (CVE-2022-21716)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 22.04 LTS:
python3-twisted 22.1.0-2ubuntu2.1

Ubuntu 16.04 ESM:
python-twisted 16.0.0-1ubuntu0.4+esm1
python-twisted-bin 16.0.0-1ubuntu0.4+esm1
python-twisted-web 16.0.0-1ubuntu0.4+esm1
python3-twisted 16.0.0-1ubuntu0.4+esm1

Ubuntu 14.04 ESM:
python-twisted 13.2.0-1ubuntu1.2+esm2
python-twisted-bin 13.2.0-1ubuntu1.2+esm2
python-twisted-web 13.2.0-1ubuntu1.2+esm2

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-5354-2

CVE-2022-21716

Package Information:
https://launchpad.net/ubuntu/+source/twisted/22.1.0-2ubuntu2.1