Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized resource identifiers, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted request to a .NET web application, aka ".NET Framework Remote Code Execution Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-057
http://www.securitytracker.com/id/1031021