iPhone bug allows hackers to steal passwords unless users update devices

Apple has fixed a major security glitch that potentially allowed hackers to steal iPhone user’s sensitive data, including passwords – but devices must be updated to avoid the risk.

The security breach meant cyber attackers could break into an iPhone by simply sending a text message containing a specially modified image.

Security experts warned that if iPhone tried to process the image, by receiving a message or visiting a webpage containing the picture, hackers could corrupt the device’s memory and access information such as website and email passwords.

The error comes down to the way Apple's software handles TIFF image files.

While iPhones can render the image normally, by tampering with a file a hacker could overload the device's memory allowing the image to execute malicious codes.

The flaw, discovered by Cisco Talos engineer Tyler Bohan, is particularly acute on Macs and also affects other iOS devices.

The vulnerability is similar to an Android Stagefright flaw that allowed hackers to infect up to one billion smartphones through a corrupt video file.