Apple has released a software patch to protect iPhone users from a vulnerability that could have let hackers take control of their device.

Apple iPhone owners can now download a security fix to patch their device against text-message hacks.

The security flaw, which was exposed last week allowed hackers and cyber criminals to potentially take control of an iPhone simply by sending the device a string of text messages.

Charlie Miller, a security adviser with Independent Security Evaluators, warned that these messages could in fact contain code for an executable file that would then embed itself in the iPhone's memory, and allow a hacker to access and control the device remotely.

Apple has sought to address the vulnerability by releasing a software patch for the iPhone which closes this loophole. The security update became available at the weekend, and users need to plug their iPhone in to their computer and synchronise the device with iTunes in order to install the patch on to their handset.

The vulnerability could enable cyber criminals to access sensitive information stored on a user's iPhone, or even assume control of the camera and microphone on the device.

A user might go to the Website for their bank on the iPhone browser and a hacker could theoretically see him enter the user name and password. He could see the data in various applications and have complete control of the phone.