A PUK code for a SIM card, which stands for Personal Unblocking Key, is an eight-digit code that enables a blocked SIM card to be unlocked. When a user repeatedly enters a wrong PIN code, such as ...

Entering a wrong PUK code ten times in a row disables the SIM card permanently. Both the PIN and the PUK codes are supplied by the operator, but only the PIN code can be changed by the user.

The attacker could just swap the SIM in the victim’s device, and perform the exploit with a SIM card that had a PIN lock and for which the attacker knew the correct PUK code.