Apple releases 'critical' iPhone patches

Apple has been forced to patch five more flaws in its popular iPhone and iPod Touch devices, three of which allow "arbitrary code execution" and could be described as 'critical'.

The firm released the iPhone OS 3.1.3 in a security notice yesterday, the first update for the device in a few months.

Apple does not rate vulnerabilities in its products in the same way as vendors like Oracle and Microsoft, but the most critical flaws affect the products' CoreAudio and ImageIO and WebKit technologies.

The flaw in CoreAudio means that playing a maliciously crafted mp4 audio file could lead to "unexpected application termination or arbitrary code execution", while viewing a maliciously crafted TIFF image could do the same owing to the ImageIO vulnerability.

Also noted is a problem with the devices' recovery mode, a feature which usually kicks in to restart the units when they are not responding.

"A memory corruption issue exists in the handling of a certain USB control message," the advisory reads. "A person with physical access to the device could use this to bypass the passcode and access the user's data."