Apple has patched a security flaw in iOS 12.4 that allowed up-to-date iPhones to be jailbroken.
According to Pwn20wnd, who developed a jailbreak exploiting the flaw, it could also have been leveraged to develop "perfect spyware".
"It is very likely that someone is already exploiting this bug for bad purposes," added Pwn20wnd while the flaw was still active.
Security researcher Jonathan Levin said that all devices that were updated to iOS 12.4, as well as any devices using an 11.x or 12.x version of iOS lower than 12.4, were exposed to what was effectively a 100+ day exploit.
Apple thanked Pwn20wnd for their assistance in identifying the security vulnerability.