Pierluigi Paganini April 14, 2016

A couple of security experts demonstrated that iOS date bug was still present in iOS devices and it was exploitable by spoofing an Apple NTP server.

Do you remember the Apple iOS date bug?

In February, the security community highlighted the existence of the embarrassing problem for Apple iOS mobile devices running 64-bit iOS 8 or higher, the issue affects the Apple iOS date and time system and could be triggered by setting the date to January 1, 1970. The news appeared in Reddit discussions warning users about a flaw that could brick iPhone forever.

“Setting the date of your iPhone to January 1st, 1970 will brick your device, according to users across the web and confirmed by iClarified. The bug will affect any 64-bit iOS device that is powered by the A7, A8, A8X, A9, and A9X. 32-bit iOS devices are reportedly not affected by this issue.” reported iClarified.

Meanwhile on Reddit the users warned other Apple users sharing the following message:“When the date of a 64-bit iOS device is set to January 1, 1970, the device will fail to boot. Connecting the device to iTunes and restoring the device to factory defaults will not put the device back in working order. Instead, a physical repair is required. When connected to public Wi-Fi, iPhone calibrates its time settings with an NTP server. Theoretically, attackers can send malicious NTP requests to adjust every iPhone’s time settings to January 1, 1970, hence brick every iPhone connected to the same network.According to /u/sarrius, worldwide Apple Store are being made aware that disconnecting the battery and reconnecting fixes the issue. It should be common knowledge to all stores worldwide by tomorrow.” 

Apple issued a patch to fix the problems, but according to experts Matt Harrigan from PacketSled and Patrick Kelley from Critical Assets the issue could be still exploited remotely.

The problem, this time, affects the way the device manage the network time protocol (NTP), an attacker can spoof time server domains in order to trigger the issue.

The attacker can spoof the time server time.apple.com to send a “malicious” day’s timestamp that trigger the issue.

“Research from PacketSled and Patrick Kelley, CISSP, CEH, MCP at Critical Assets proves it possible to remotely brick iDevices over-the-air. The team built the exploit based on Zach Straley’s research which exposed a flaw in iOS when a user to manually set the date of an iPhone or iPad to January. 1, 1970.” states a blog post published on PacketSled.

In the video PoC published by the experts they demonstrate how set up a bogus Wi-Fi hotspot with a Raspberry Pi that spoof an Apple’s NTP servers to pass the 1/1/1970 date that triggers the iOS date bug.

https://youtu.be/zivWTwOjEME

When the device receives the data it reach an unstable state associated with a high temperature of the mobile (up to 54°C) that brick it.

“This starts a chain reaction of software instability resulting in an observed temperature up to 54°C… which is hot enough to brick a device.” continues the post.

The duo will publish soon a detailed paper on their test.

Apple solved the issue in the last iOS 9.3.1 update.

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Pierluigi Paganini 

(Security Affairs – iOS date bug, hacking)