Several security issues were fixed in Zsh.
It was discovered that Zsh incorrectly handled certain enviroment variables. An attacker could possibly use this issue to gain privileged access to the system. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10070)
8 March 2018
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Zsh.
It was discovered that Zsh incorrectly handled certain enviroment variables. An attacker could possibly use this issue to gain privileged access to the system. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10070)
It was discovered that Zsh incorrectly handled certain inputs. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10071)
It was discovered that Zsh incorrectly handled some symbolic links. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10072)
It was discovered that Zsh incorrectly handled certain errors. An attacker could possibly use this issue to cause a denial of service. (CVE-2016-10714)
It was discovered that Zsh incorrectly handled certain commands. An attacker could possibly use this to execute arbitrary code. (CVE-2017-18205)
It was discovered that Zsh incorrectly handled certain symlinks. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2017-18206)
It was discovered that Zsh incorrectly handled certain inputs. An attacker could possible use to execute arbitrary code. This issue only affected Ubuntu 17.10. (CVE-2018-7548)
It was discovered that Zsh incorrectly handled certain inputs. An attacker could possibly use this to cause a denial of service. (CVE-2018-7549)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to restart Zsh to make all the necessary changes.