==========================================================================
Ubuntu Security Notice USN-3593-1
March 08, 2018

zsh vulnerabilities
==========================================================================

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

- Ubuntu 17.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in Zsh.

Software Description:
- zsh: shell with lots of features

Details:

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)

Update instructions:

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

Ubuntu 17.10:
  zsh                             5.2-5ubuntu1.1

Ubuntu 16.04 LTS:
  zsh                             5.1.1-1ubuntu2.1

Ubuntu 14.04 LTS:
  zsh                             5.0.2-3ubuntu6.1

After a standard system update you need to restart Zsh to make
all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3593-1
  CVE-2014-10070, CVE-2014-10071, CVE-2014-10072, CVE-2016-10714,
  CVE-2017-18205, CVE-2017-18206, CVE-2018-7548, CVE-2018-7549

Package Information:
  https://launchpad.net/ubuntu/+source/zsh/5.2-5ubuntu1.1
  https://launchpad.net/ubuntu/+source/zsh/5.1.1-1ubuntu2.1
  https://launchpad.net/ubuntu/+source/zsh/5.0.2-3ubuntu6.1