Apple fanboys will have to chant the mantra that Steve Jobs protects them from all security attacks with even more intensity over the next few months.

According to Sophos a website that has made it simple for iPhone and iPad users to jailbreak their devices is not just a nuisance for Apple, who want to discourage owners from jailbreaking their devices, but is also a portent for future malicious attacks.

Owners of Apple gadgets, including the recently launched iPad 2, are presented with an easy way to jailbreak them, opening up the possibility of installing apps that have not been approved by the official Apple AppStore. Normally, jailbreaking requires users to connect their device to a computer before they can start to tamper with the set-up of their iPhone or iPad and gain access to the Cydia underground app store.

The drive-by jailbreak is possible because the website exploits a vulnerability in the way that the mobile edition of Safari (the default browser used in the iOS operating system) handles PDF files. Because Apple has not yet patched this latest vulnerability, iPad and iPhone users could be at risk from hackers if they chose to exploit the same vulnerability to install malicious code.

Graham Cluley, senior technology consultant at Sophos said that cybercriminals would be able to create booby-trapped webpages that could- if visited by an unsuspecting iPhone, iPod Touch or iPad owner - run code on visiting devices without the user's permission. He added that Apple will be furious that this vulnerability has been made public in this way, and that they have not yet got a patch to protect their millions of users.

Sophos's experts have added detection of the exploit code as Exp/PdfEx-ER, but as Apple does not allow anti-virus software to be listed in the official iPhone AppStore there is no on-device protection available for users. Apple can't allow the listing of AV software because if it does it has to admit how vulnerable it is to a serious virus attack.  It would prefer people just think that only Microsoft suffers from malware.

However Cluely warns that praying to Jobs might not be enough soon. A website like JailBreakMe is making it easy to jailbreak your iPhone or iPad - but it could also be said to be giving a blueprint to malicious hackers on how to infect devices with malware.

"There are many cybercriminals who would love to infect iPhones and iPads, and eyes will now be turning towards Apple to see how quickly they can issue a patch for iOS to close this vulnerability," he said.