Severity Rating: Important
Revision Note: V1.3 (September 24, 2014): Bulletin revised to correct a missing Server Core installation entry in the Affected Software table for Microsoft .NET Framework 4 when installed on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (2898855). This is an informational change only. Customers running this affected software on Server Core installations who have already applied the 2898855 update do not need to take any action. Customers running this affected software on Server Core installations who have not already installed the update should do so to be protected from the vulnerabilities addressed in this bulletin.
Summary: This security update resolves two publicly disclosed vulnerabilities and one privately reported vulnerability in Microsoft .NET Framework. The most severe vulnerability could allow elevation of privilege if a user visits a specially crafted website or a website containing specially crafted web content. In all cases, however, an attacker would have no way to force users to visit such websites. Instead, an attacker would have to convince users to visit the compromised website, typically by getting them to click a link in an email message or in an Instant Messenger message that takes them to the attacker’s website.