Apple's iPhone 3G is vulnerable to attacks after the latest software update, iOS 4.3, fails to defend the device, according to a security firm.
Security fixes include protection against malicious Tiff image files and some memory corruption issues in WebKit.
Graham Cluley, senior technology consultant at Sophos, says that while the update is compatible with the iPhone 3GS and later models, such as the third-generation iPod Touch and the iPad, it lacks security patches for older models, such as the iPhone 3G and iPod Touch.
"If you have an earlier iPhone or iPod Touch, your device is potentially vulnerable to attacks which could exploit these known security holes, and there is no official patch available for you to protect yourself," said Cluley.
"That's bad news for the very many people who still have an iPhone 3G."