With Ansible and apt, how do I update bash for CVE-2014-6271 remote security vulnerability?

Question

Given the bash remote code execution vulnerability announced on September 24, 2014 , how can I upgrade my apt-based systems using Ansible?

Answer 1

Here is my preferred solution in a fairly uniform environment. The advantage of this is that the update does not take much time in the future, unlike the template version=latestthat others use.

- name: update apt cache if not done today
  apt: update_cache=yes cache_valid_time=86400

# http://seclists.org/oss-sec/2014/q3/650
- name: ensure secure ansible, ubuntu 1204 edition
  apt: pkg=bash=4.2-2ubuntu2.5 state=present
  when: ansible_distribution=='Ubuntu' and ansible_distribution_version=='12.04'

- name: ensure secure ansible, ubuntu 1404 edition
  apt: pkg=bash=4.3-7ubuntu1.3 state=present
  when: ansible_distribution=='Ubuntu' and ansible_distribution_version=='14.04'

# based on the following gist and comments below. there have been several exploits, this covers them well.
# https://gist.github.com/kacy/2b9408af04c71fab686e
- name: ensure bash is not vulnerable to 201409 problem
  shell: "foo='() { echo not patched; }' bash -c foo"
  register: command_result
  ignore_errors: yes
  failed_when: "'command not found' not in command_result.stderr"

: apt-cache , . . , , . , /.

SO user @jarv . , apt, , . ( , ). jarv , .

- name: Check if we are vulnerable
  shell: executable=/bin/bash env x='() { :;}; echo vulnerable'  bash -c "echo this is a test"
  register: test_vuln

- name: Apply bash security update if we are vulnerable
  apt: name=bash state=latest update_cache=true
  when: "'vulnerable' in test_vuln.stdout"

- name: Check again and fail if we are still vulnerable
  shell: executable=/bin/bash env x='() { :;}; echo vulnerable'  bash -c "echo this is a test"
  when: "'vulnerable' in test_vuln.stdout"
  register: test_vuln
  failed_when: "'vulnerable' in test_vuln.stdout"

. , Ansible, @ansible :

:

ansible all -m apt -a 'update_cache=yes name=bash state=latest'

:

- name: update apt
  command: apt-get update

- name: update bash
  command: apt-get --only-upgrade install bash

- name: check bash fix
  command: env x='() { :;}; echo vulnerable' bash -c "echo this is a test"
  register: command_result
  failed_when: "'error' not in command_result.stderr"