According to ZecOps, for years hackers could use a security hole to crack mail. The vulnerability was found in all iOS starting with iOS 6 and ending with iOS 13.4.1. In iOS 13.4.5, Apple fixed the problem.
Attackers did not hack into ordinary users. Their goals were employees of Fortune, the head of the Japanese transport company, influential residents of Germany, officials and one European journalist. [MacRumors]