USN-5325-1: Zsh vulnerabilities

Releases

• Ubuntu 21.10
• Ubuntu 20.04 LTS
• Ubuntu 18.04 ESM
• Ubuntu 16.04 ESM

Packages

• zsh - shell with lots of features

Details

Sam Foxman discovered that Zsh incorrectly handled certain inputs.
An attacker could possibly use this issue to regain dropped privileges.
(CVE-2019-20044)

It was discovered that Zsh incorrectly handled certain inputs.
An attacker could possibly use this issue to execute arbitrary code.
(CVE-2021-45444)

Update instructions

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

Ubuntu 21.10

• zsh-static - 5.8-6ubuntu0.1
• zsh - 5.8-6ubuntu0.1

Ubuntu 20.04

• zsh-static - 5.8-3ubuntu1.1
• zsh - 5.8-3ubuntu1.1

Ubuntu 18.04

• zsh-static - 5.4.2-3ubuntu3.2
• zsh - 5.4.2-3ubuntu3.2

Ubuntu 16.04

• zsh-static - 5.1.1-1ubuntu2.3+esm1
  Available with Ubuntu Pro
• zsh - 5.1.1-1ubuntu2.3+esm1
  Available with Ubuntu Pro

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

References

• CVE-2021-45444
• CVE-2019-20044