Linux and Mac: fix your bash vulnerability

September 25, 2014Maxime Thoonsen1 min read

Today a major security vulnerability has been found in GNU Bash. Bash is used by almost every Linux AND Unix systems.
Ubuntu and Mac OS are examples of OS using it. It's highly advised to update your OS.
If you want to know more about this, you should read this article.

How can I checked if my OS is vulnerable?

This command line can tell you if your OS is vulnerable.

env x='() { :;}; echo vulnerable' bash -c 'echo this is a test'

If you see "vulnerable" printed then you need to update the bash of your system.

wtf
(Image from Robert Graham)

How to fix it?

Some patches has been released so you can already update your Bash version to a safer one but they haven't fixed all the problems. You can check the current status of patches for Ubuntu here.
Once they will have fixed it, you will be able to update to a safe version of Bash.

For Ubuntu you just have to update your bash package:

sudo apt-get update && sudo apt-get install bash

Mac users should have a look at this post

Sources:

Maxime Thoonsen

Maxime Thoonsen

Theodo - CTO