iOS 9.3.5 fixes three security vulnerabilities that were exploited by a security company called the NSO Group, which allowed them to invisibly tracks a target’s mobile phone and intercept communications, including the ability to read text messages, emails, track calls and contacts, as well as record sounds, collect passwords and trace the whereabouts of the phone user.
According to NYT "The vulnerabilities were brought to light after UAE human rights activist Ahmed Mansoor received some suspicious text messages. He shared the messages with Citizen Lab who then brought in Lookout to help examine the code. Together they discovered the three previously unknown iOS vulnerabilities and informed Apple about their existence".
iOS 9.3.5 is now rolling out as a free update through Software Update or can be downloaded via iTunes to all supported iPod Touch, iPhone, and iPad devices.
