Severity Rating: Important
Revision Note: V1.1 (February 28, 2014): Bulletin revised to announce a detection change in the 2868626 update for Windows 8.1 for 32-bit Systems, Windows 8.1 for x64-based Systems, Windows RT 8.1, and Windows Server 2012 R2. This is a detection change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow denial of service when an affected web service processes a specially crafted X.509 certificate.

Severity Rating: Important
Revision Note: V1.1 (February 28, 2014): Bulletin revised to announce a detection change in the 2916036 update for Windows 8.1 for 32-bit Systems, Windows 8.1 for x64-based Systems, Windows Server 2012 R2, and Windows RT 8.1. This is a detection change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves a publicly disclosed vulnerability in Microsoft XML Core Services included in Microsoft Windows. The vulnerability could allow information disclosure if a user views a specially crafted webpage using Internet Explorer. An attacker would have no way to force users to view specially crafted 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 users to an attacker’s website, or by getting them to open an attachment sent through email.

Severity Rating: Critical
Revision Note: V1.1 (February 28, 2014): Bulletin revised to announce a detection change in the 2912390 update for Windows 8.1 for 32-bit Systems, Windows 8.1 for x64-based Systems, Windows RT 8.1, and Windows Server 2012 R2. This is a detection change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker would have no way to force users to view specially crafted 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 users to an attacker’s website, or by getting them to open an attachment sent through email.

Severity Rating: Critical
Revision Note: V1.1 (February 28, 2014): Bulletin revised to announce a detection change in the 2900986 update for Windows 8.1 for 32-bit Systems, Windows 8.1 for x64-based Systems, Windows RT 8.1, and Windows Server 2012 R2. This is a detection change only. There were no changes to the update files. Customers who have already successfully updated their systems do not need to take any action.
Summary: This security update resolves a privately reported vulnerability that is currently being exploited. The vulnerability exists in the InformationCardSigninHelper Class ActiveX control. The vulnerability could allow remote code execution if a user views a specially crafted webpage with Internet Explorer, instantiating the ActiveX control. 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.