Technical Information

Brief overview of the risk:
A cross-site scripting (XSS) vulnerability exists in ASP.NET MVC that could allow an attacker to inject a client-side script into the user’s web browser. The script could spoof content, disclose information, or take any action that the user could take on the site on behalf of the targeted user.

Detailed Information on the risk:

This security update resolves a publicly disclosed vulnerability in ASP.NET MVC. The vulnerability could allow security feature bypass if an attacker convinces a user to click a specially crafted link or to visit a webpage that contains specially crafted content designed to exploit the vulnerability. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through a web browser, and then convince a user to view the website. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, 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, or by getting them to open an attachment sent through email.

Further information on this exploit is available at : MS14-059

ASP.NET MVC 2.0
ASP.NET MVC 3.0
ASP.NET MVC 4.0
ASP.NET MVC 5.0
ASP.NET MVC 5.1