iOS 9 date bug: iPhones could be forced to break by connecting to any Wi-Fi network

The problem mirrors the ‘January 1, 1970’ bug that was thought to have been fixed earlier this year – but researchers have found another way in

An attendee inpsects the new iPhone SE during an Apple special event at the Apple headquarters on March 21, 2016 in Cupertino, California (Getty)

Any iPhone could be shut down just by connecting to a Wi-Fi network.

A new bug has been found by security researchers that could allow hackers to cause problems for phones without their owner ever knowing.

The new problem is a development of the “January 1, 1970” bug that was made public, and then fixed, earlier this year. But it uses a roundabout trick over Wi-Fi that exploits much the same problem.

That bug works by tricking phones into thinking that the date is 46 years ago. The phone can’t deal with the date January 1, 1970, and so the phone breaks down once that date is set.

In previous examples, it required users to actually set the date that way themselves. That was usually done either by taking hold of somebody’s phone or through tricking people, such as by pretending that changing the date would activate a special “retro” mode.

While the previous problem has since been fixed, the new exploit uses problems with the Wi-Fi network to trick phones into resetting their date. It essentially works in the same way as the old trick, but works over the network.

Researchers Patrick Kelley and Matt Harrigan found that they could hijack the network time protocol (NTP) which the phone uses to check what the date and time is. The security researchers could pretend to be an NTP server, and instead tell the phone that it is January 1, 1970 – causing issues for the phones.

The researchers say that the phones overheat once they are hit by the problems, which causes them to break. But Apple's phones and iPads have safeguards in them that let them avoid potential problems caused by running too hot.

Users can stay safe from the bug by making sure that they don’t connect to suspect Wi-Fi networks, which security experts advise anyway. But that might be more difficult than it sounds, since hackers can easily trick devices into connecting to suspect networks without their owner ever knowing.

Phones and other computers know which Wi-Fi networks to connect to by looking for those with names that they have used before. But that could be spoofed by people setting up fake Wi-Fi networks with the same names as real ones – and the same could be done without tricking people, and just by offering free Wi-Fi that looks legitimate.

The problem also won’t affect phones that are updated to the newest iOS 9.3 update, which was released last month.