iOS 9.3.5 Fixes Massive Security Flaw: What IT Needs To Know

8 Steps To Building A Successful Cyber-Security Career

Stop. Drop what you're doing and update your iPhone. A new security hole found by researchers is critically dangerous. The vulnerability could lead to remote code execution, allowing hackers to completely take over an iPhone remotely. Apple has already issued a patch via iOS 9.3.5 and recommends everyone update immediately.

IT managers need to get the word out to employees right away or even remotely push the update. Here's why.

Ahmed Mansoor, a United Arab Emirates-based human rights activist, recently received a suspicious text message. The message asked him to click on an embedded link. Rather than click, Mansoor smartly forwarded the message to security researchers at the University of Toronto.

Citizen Lab at the University of Toronto partnered with Lookout to explore what might have happened had Mansoor clicked the link. It's a good thing Mansoor listened to his gut. The researchers found that the link would have force-installed a program through three previously unknown vulnerabilities in iOS. The app could have then taken over the phone and allowed the attackers to do what they wished.

The spyware, called Pegasus, is the most advanced attack Citizen Lab says it has seen, "because it takes advantage of how integrated mobile devices are in our lives and the combination of features only available on mobile -- always connected (WiFi, 3G/4G), voice communications, camera, email, messaging, GPS, passwords, and contact lists," explained Citizen Lab in a blog post.

"It is modular to allow for customization and uses strong encryption to evade detection. Lookout's analysis determined that the malware exploits three zero-day vulnerabilities, [called] Trident, in Apple iOS."

[See Mobile Messaging Apps: 8 Tips for Keeping Your Workplace Secure.]

The researchers contacted Apple earlier this month and the company moved to plug the security holes very quickly.

iOS 9.3.5 covers an information leak at the kernel level, a kernel memory corruption that can lead to jailbreak, and a memory corruption in WebKit that leaves Safari open to attack. These would allow hackers to jailbreak an iPhone remotely and install surveillance software that could spy undetected.

Businesses, especially those that have mobile devices in the field, need to protect against this vulnerability as quickly as possible.

iOS 9.3.5 can be downloaded over the air directly from Apple.