iPhone calendar spam virus is one of the most seen and very common, but a super intrusive adware an iOS user might face. As I have the first-hand experience with the spam, I can confirm that it is ugly and annoying.
Unc0ver has released Unc0ver 5.0.1, which can jailbreak iOS devices through 11.0-13.5. They were able to produce the tools within a few days of their announcement about the new-found exploit. The team claims that they have extensively tested across a range of devices