CVE-2014-6271 fix for ubuntu bash

gistfile1.yml

---
- hosts: all
  user: root
  sudo: true

  tasks:
    - 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"

As for the last task, you could use the shellshocker site script to easily check if all vulnerabilities were resolved by doing:

- name: check vulnerability status fix
  shell: curl https://shellshocker.net/shellshock_test.sh | bash
  register: command_result

- debug: var=command_result.stdout_lines