Once you’ve used the TIFF exploit to Jailbreak your iPod touch or iPhone it’s a bad idea to leave your browser open to the fairly serious vulnerability, luckily someone has created a patch and it’s dead simple to install.

Step 1: Download patch-graphics from here. (Right-click, save as for best results. You might also have to remove the file extension .html depending on your web browser. You should be left with an extensionless file called patch-graphics)
Step 2: Using SFTP, upload the file to your iPod touch or iPhone to the /Applications/ directory.
Step 3: SSH into your iPod touch or iPhone and run /bin/chmod a+w /Applications/*
Step 4: Run the patch using the following command ./Applications/patch-graphics A bunch of text should fill the screen and you should be returned to the prompt.
Step 5: Success, you’re done. Visit the web with impunity.