An elevation of privilege vulnerability exists when Microsoft IIS Server fails to check the length of a buffer prior to copying memory to it.An attacker who successfully exploited this vulnerability can allow an unprivileged function ran by the user to execute code in the context of NT AUTHORITY\system escaping the Sandbox.The security update addresses the vulnerability by correcting how Microsoft IIS Server sanitizes web requests., aka 'Microsoft IIS Server Elevation of Privilege Vulnerability'.