I wonder how Frank Castle was able to bypass the War Machine armor’s security. I’m sure Tony Stark made sure only a select number of people, most likely his close circle, would be able to use the armor.
My theory is Nick Fury JR knew some override and gave it to the Punisher. Afterall, his dad Nick Fury was able to gain control of the Iron Man suit when he fought against Tony Stark.
From – The Punisher Vol. 1 #219