On Tuesday, Apple released the latest version of their iPhone OS, with the intention of enhancing security on the iPhone and iPod Touch.
The update, dubbed iPhone OS 3.1.3, contains several bug fixes and security patches, the first of which protects iPhones and iPods from malicious code in audio and picture files.
iPhone 3.1.3 also patches up other security issues. One concerns a vulnerability where someone with physical access to a device could bypass the lock code and access data. A second set of fixes addresses problems with Webkit, or the engine that drives the web browser. They keep the phone from remotely accessing bad files and servers.
As far as bug fixes are concerned, there's a change that stops crashes when using the Japanese Keyboard, and another that increases the accuracy of the battery meter on iPhone 3GS.
Source: PC World