Microsoft Windows 8.1, Windows Server 2012 R2, Windows RT 8.1, and Windows 10 Gold, 1511, and 1607, when the lock screen is enabled, do not properly restrict the loading of web content, which allows physically proximate attackers to execute arbitrary code via a (1) crafted Wi-Fi access point or (2) crafted mobile-broadband device, aka "Windows Lock Screen Elevation of Privilege Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-112