Mozilla patched a zero day uncovered at Pwn2Own in Firefox in 22 hours on Friday.

On the first day of Pwn2Own 2017 hackers poked holes in Adobe Reader, Apple Safari, Microsoft Edge, and Ubuntu Linux.

Apple Safari and Adobe Flash have proved to be Pwn2Own 2016’s biggest punching bags so far—hackers took down both, earning $282,500 in prizes at the first day of the annual hacking challenge in Vancouver on Wednesday. There were four successful attempts, one partial, and one failed attempt at the competition, which is held in tandem with the...