This security update resolves a privately reported vulnerability in Microsoft Report Viewer. The vulnerability could allow information disclosure if a user views a specially crafted Web page. In all cases, however, an attacker would have no way to force a user to visit the Web site. Instead, an attacker would have to persuade a user to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes the user to the vulnerable Web site.

This security update is rated Important for all supported editions of Microsoft Visual Studio 2005 and Microsoft Report Viewer 2005 Redistributable Package. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the manner in which the Microsoft Report Viewer control validates parameters within a data source. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.

For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update at the earliest opportunity using update management software, or by checking for updates using the Microsoft Update service.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. None

Reference: http://www.microsoft.com/technet/security/Bulletin/MS11-067.mspx