April 2012 Microsoft Security Bulletin Release

This security update resolves five privately reported vulnerabilities in Internet Explorer. The most severe vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited any of these vulnerabilities could gain the same user rights as the current user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user or application runs or installs a specially crafted, signed portable executable (PE) file on an affected system.

This security update resolves one privately reported vulnerability in Microsoft .NET Framework. The vulnerability could allow remote code execution on a client system if a user views a specially crafted webpage using a web browser that can run XAML Browser Applications (XBAPs). Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. The vulnerability could also allow remote code execution on a server system running IIS, if that server allows processing ASP.NET pages and an attacker succeeds in uploading a specially crafted ASP.NET page to that server and then executes the page, as could be the case in a web hosting scenario. This vulnerability could also be used by Windows .NET applications to bypass Code Access Security (CAS) restrictions. In a web browsing attack scenario, an attacker could host a website that contains a webpage that is used to exploit this vulnerability. In addition, compromised websites and websites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these websites. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes users to the attacker’s website.

This security update resolves a privately disclosed vulnerability in Windows common controls. The vulnerability could allow remote code execution if a user visits a website containing specially crafted content designed to exploit the vulnerability. In all cases, however, an attacker would have no way to force users to visit such a website. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes them to the attacker’s website. The malicious file could be sent as an email attachment as well, but the attacker would have to convince the user to open the attachment in order to exploit the vulnerability.

This security update resolves two privately reported vulnerabilities in Microsoft Forefront Unified Access Gateway (UAG). The more severe of the vulnerabilities could allow information disclosure if an attacker sends a specially crafted query to the UAG server.

This security update resolves a privately reported vulnerability in Microsoft Office and Microsoft Works. The vulnerability could allow remote code execution if a user opens a specially crafted Works file. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.