Apple have today released updates to Bash for Lion, Mountain Lion and Mavericks. All users are recommended to update to Bash version 3.2.53(1) to patch the recently found “Shellshock” exploit.

At the time of writing the update for 10.9 wasn’t coming through OS X’s built in ‘Software Update’. The updates are available for download and install here:

http://support.apple.com/kb/DL1767 – OS X Lion
http://support.apple.com/kb/DL1768 – OS X Mountain Lion
http://support.apple.com/kb/DL1769 – OS X Mavericks