Digital Ocean provided this useful tutorial on how to protect yourself from the shellshock vulnerability in bash.
If you manage a bunch of servers, it might be easier to do this with a tool like ansible which can run the command accross many servers. It's pretty easy:
You need to run two commands:
ansible All -a "apt-get update" -s -i hosts --user=<remote_user>
ansible All -a "apt-get install --only-upgrade bash" -s -i hosts --user=<remote_user>
- -s tells the command to use sudo
- --user specifies your remote user to log into the box with
- -i specifies your hosts file to use (see below)
Where All is all your hosts, and hosts is your hosts file. Your hosts file might look something like this:
[All] 188.8.131.52 ...