TL;DR: Microsoft's Secure Boot bootloader is vulnerable to an attack where you use a (Microsoft-signed) supplemental boot policy instead of a regular boot policy, effectively removing the Secure Boot lock and allowing to run unsigned code.
This affects locked devices (Windows RT, Phone, ...) and might be used for jailbreaking devices as well as to attack their security.
This affects locked devices (Windows RT, Phone, ...) and might be used for jailbreaking devices as well as to attack their security.