The Windows Installer in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows local users to gain privileges via a crafted application that invokes the repair feature for a different application, aka "Windows Installer Repair Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-049
http://www.securitytracker.com/id/1030719