A flaw in iOS 8 would allow attackers to render devices running the mobile OS useless if they're within range of a fake wireless hotspot, according to researchers from security firm Skycure.
The vulnerability exploits an issue in how iOS 8 handles SSL certificates. By manipulating the certificates, researchers found they were able to get apps running on iPads, iPhone and iPods as well as the OS to crash. In other instances, the researchers placed the devices in a constant reboot cycle.
Yair Amit and Adi Sharabani, Skycure's CTO and CEO, respectively, discussed the flaw, called "No iOS Zone," Tuesday during a session at the RSA conference and talked about their findings in a blog post on Wednesday.
While attackers need to have control over a wireless network to send the bogus SSL certificates, the researchers found that pairing the SSL certificate flaw with an older threat they named WiFiGate makes this scenario possible.
WiFiGate takes advantage of a feature that allows mobile carriers to configure settings in iOS devices. Carriers, for example, have preprogrammed iOS devices to automatically connect to Wi-Fi networks they have set up for their subscribers. In the U.K., for instance, iPhones running on Vodafone's network will connect to the Wi-Fi networks named "1WifiVodafone1x" or "Auto-BTWiFi", according to a Skycure blog post on the WiFiGate threat. Customers can't disable or change these preconfigured Wi-Fi settings. The only way to protect against WiFiGate attacks is to turn off Wi-Fi on a device, the post said.
Knowing the names of the preprogrammed wireless networks, information that can be found in iOS, attackers could create a fake Wi-Fi network that Apple mobile devices connect to by default. Next, they could launch an attack that uses the SSL certificate flaw and cripple the devices, Skycure said. If people figure out that the Wi-Fi network is responsible for the attack -- and their device is constantly rebooting -- they would be unable to turn off the Wi-Fi connection and stop the assault.
Attacks using the SSL flaw haven't been reported, but such an assault could prove "catastrophic" if launched in a location with heavy mobile traffic, such as an airport or finance center like Wall Street, said Skycure. With nearly every program in Apple's App Store using SSL, a common security technique that validates a website, Skycure realized the flaw "could lead to a serious business impact."
Since the exploit hasn't been fixed, Skycure isn't sharing technical details, but has informed Apple about the issue. The companies are working together on a resolution.
Skycure recommends people upgrade to the latest version of iOS since the update may have fixed some of the threats and avoid suspicious free networks, especially those that cause their devices to constantly crash or reboot.