If a user opened an infected audio or image file, or hit a malicious FTP server, hackers could run code remotely, taking control of the device.
Another of the exploits could allow hackers to bypass the password on a locked device, as long as they had access to the actual device.
The update is for those with iPhone OS 3.1.3.
Full support page here: About the security content of iPhone OS 3.1.3 and iPhone OS 3.1.3 for iPod touch
Written by: Andre Yoskowitz @ 3 Feb 2010 13:50