On 24th of September, a standard util called “bash” on every Linux System declared to be vulnerable. Vulnerable systems are Linux, BSD, Mac OS X and other systems use “bash” as a command interpreter.
In order to identify your server as vulnerable, please try the command below on your cli:
env x='() { :;}; echo vulnerable' bash -c "echo this is a test"
If you get “vulnerable” line upon pressing enter, you should update your server as soon as possible