SHELL SHOCKER Making Rounds, Update your Bash!

Dfg

Do this before anything,

if CentOs

yum -update bash

Read these articles:

https://shellshocker.net/
http://bashsmash.ccsir.org/
http://www.shellshocktest.com/
https://access.redhat.com/articles/1200223
http://blog.sucuri.net/2014/09/bash-vulnerability-shell-shock-thousands-of-cpanel-sites-are-high-risk.html


NIX System Administrators

You’re in luck with this one, identifying if you’re vulnerable is easier than previous vulnerabilities. Log into your server and via terminal run this command:

[root@yourawesomeserver ~]# env x='() { :;}; echo vulnerable' bash -c 'echo hello'

If you are vulnerable it will return:

[root@yourawesomeserver ~]# env x='() { :;}; echo vulnerable' bash -c 'echo hello'
vulnerable
hello

To fix it will depend on your NIX distribution but you will want to reinstall or update, which ever you prefer:

#sudo apt-get install bash

- or -

#sudo yum update bash

Once complete, rerun the test and you will get:

[root@yourawesomeserver ~]# env x='() { :;}; echo vulnerable' bash -c 'echo hello'
bash: warning: x: ignoring function definition attempt
bash: error importing function definition for `x'
hello


I patched our server, so we're safe, but you better go patch your systems NOW!