Apple is urging iPhone owners to update their iOS immediately to patch a new security flaw which could give hackers control of their device.
Known as Broadpwn, the bug affects the Wi-Fi chips found in both Android and Apple smartphones and allows an attacker to take over a device remotely while it searches for Wi-Fi.
"An attacker within range may be able to execute arbitrary code on the Wi-Fi chip," Apple wrote on its blog.
The troubling bug only requires users' iOS device to have Wi-Fi turned on for hackers to gain access to assume control of the phone's processor - the central computer runs all the basic system instructions.
Even a passcode will not protect iPhones from the bug, which can bypass the security feature toexploit the weakness.
The affected Wi-Fi chips are found in every Apple device from the iPhone 5 and fourth-generation iPad onward, with the sixth-generation iPod touch also prone to the exploit.
Broadpwn has also affected a broad range of devices from companies like HTC, LG and Samsung, although Google patched the exploit in Android devices on July 5 after listing it as a critical security flaw.
To download iOS 10.3.3. iPhone owners can use the Software Update mechanism in Settings → General → Software Update on their iOS device.
Alternatively, users can connect their device to iTunes via a USB cable, select their device from the list, click the Summary tab, and then click the Check for Update button to download iOS.
WHAT ELSE DOES iOS 10.3.3 OFFER?
While the latest update will fix the security flaw, Apple's updated iOS 10.3 offers a number of new features.
If you own a pair of Apple's wireless AirPod headphones, iOS 10.3 will let you add the product to the to Find My iPhone feature.
Impressively, the individual AirPods will ping when you're trying to locate them.
The update also gives shortcuts to the latest apps you used and better features for Apple Music when using CarPlay in your vehicle.
Other improvements include movies being available across your Apple devices when a movie is rented through iTunes and the addition of Apple File System - a new feature designed to make your device faster, by prioritising actions like opening apps.