The Protected Mode feature in Microsoft Internet Explorer 7 through 10 on Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows Server 2012, and Windows RT does not properly implement the Integrity Access Level (aka IL) protection mechanism, which allows remote attackers to obtain medium-integrity privileges by leveraging access to a low-integrity process, aka "Process Integrity Level Assignment Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18031
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-059