USN-3294-1: Bash vulnerabilities
Ubuntu Security Notice USN-3294-1
17th May, 2017
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 17.04
- Ubuntu 16.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
Several security issues were fixed in Bash.
- bash - GNU Bourne Again SHell
Bernd Dietzel discovered that Bash incorrectly expanded the hostname when
displaying the prompt. If a remote attacker were able to modify a hostname,
this flaw could be exploited to execute arbitrary code. This issue only
affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10.
It was discovered that Bash incorrectly handled the SHELLOPTS and PS4
environment variables. A local attacker could use this issue to execute
arbitrary code with root privileges. This issue only affected Ubuntu 14.04
LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7543)
It was discovered that Bash incorrectly handled the popd command. A remote
attacker could possibly use this issue to bypass restricted shells.
It was discovered that Bash incorrectly handled path autocompletion. A
local attacker could possibly use this issue to execute arbitrary code.
This issue only affected Ubuntu 17.04. (CVE-2017-5932)
The problem can be corrected by updating your system to the following package version:
- Ubuntu 17.04:
- bash 4.4-2ubuntu1.1
- Ubuntu 16.10:
- bash 4.3-15ubuntu1.1
- Ubuntu 16.04 LTS:
- bash 4.3-14ubuntu1.2
- Ubuntu 14.04 LTS:
- bash 4.3-7ubuntu1.7
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.