Ubuntu 17.04 USN-3294-1 Critical: Bash Code Execution Risk

ubuntu

May 17, 2017

Several security issues were fixed in Bash.

Summary

Several security issues were fixed in Bash.

Software Description:

- bash: GNU Bourne Again SHell

Details:

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.

(CVE-2016-0634)

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.

(CVE-2016-9401)

It was discovered that Bash incorrectly handled path autocompletion. A

local attacker could possibly use this issue to execute a...

Read the Full Advisory

Topics Covered

security advisory code execution remote access critical flaw ubuntu attack vector bash

Update Instructions

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

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

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