Apple has released an operating system update OS 3.1.3 for: iPhone OS 1.0 through 3.1.2, iPhone OS for iPod Touch 1.1 through 3.1.2.
If fixes some bugs including one that caused crashing apps on devices with a Japanese keyboard and improves the accuracy of the battery level reporting.
There was a glitch that playing a maliciously crafted mp4 orTIFF image could lead to code execution or termination due to a buffering issue. There was also an issue with memory corruption with USB controls that allowed access to personal data on a locked iPhone or iPod Touch. The was also a problem with an opening for malicious code and data-minig in FTP functions in the WebKit browser. There was also a glitch with HTML5
Apple says they have fixed the aforementioned issues in the update, but does not reveal security threats or secrets.