Severity Rating: Important
Revision Note: V1.0 (May 13, 2014): Bulletin published.
Summary: This security update resolves one privately reported vulnerability in an implementation of the MSCOMCTL common controls library. The vulnerability could allow security feature bypass if a user views a specially crafted webpage in a web browser capable of instantiating COM components, such as Internet Explorer. In a web-browsing attack scenario, an attacker who successfully exploited this vulnerability could bypass the Address Space Layout Randomization (ASLR) security feature, which helps protect users from a broad class of vulnerabilities. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use this ASLR bypass vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability that could take advantage of the ASLR bypass to run arbitrary code.

Severity Rating: Important
Revision Note: V1.1 (May 13, 2014): V1.1 (May 13, 2014): Corrected the update replacement for the Microsoft Office 2010 (proofing tools) (2878284) update.
Summary: This security update resolves two privately reported vulnerabilities in Microsoft Office. The most severe vulnerability could allow remote code execution if a user opens an Office file that is located in the same network directory as a specially crafted library file. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Severity Rating: Critical
Revision Note: V1.1 (May 1, 2014): Bulletin revised to specify that the latest cumulative security update for Internet Explorer must be installed prior to installing MS14-021. See the Update FAQ for details.
Summary: This security update resolves a publicly disclosed vulnerability in Internet Explorer. The vulnerability could allow remote code execution if a user views a specially crafted webpage using an affected version of Internet Explorer. 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.

Severity Rating: Important
Revision Note: V1.0 (April 8, 2014): Bulletin published.
Summary: This security update resolves a privately reported vulnerability in Microsoft Office. The vulnerability could allow remote code execution if a user opens a specially crafted file in an affected version of Microsoft Publisher. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Severity Rating: Critical
Revision Note: V1.0 (April 8, 2014): Bulletin published.
Summary: This security update resolves one publicly disclosed vulnerability and two privately reported vulnerabilities in Microsoft Office. The most severe of these vulnerabilities could allow remote code execution if a specially crafted file is opened or previewed in an affected version of Microsoft Office software. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Severity Rating: Critical
Revision Note: V1.0 (March 11, 2014): Bulletin published.
Summary: This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user opens a specially crafted image 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.

Severity Rating: Important
Revision Note: V1.0 (March 11, 2014): Bulletin published.
Summary: This security update resolves one publicly disclosed vulnerability and one privately reported vulnerability in Microsoft Windows. The more severe of these vulnerabilities could allow elevation of privilege if an attacker logs on to the system and runs a specially crafted application. An attacker must have valid logon credentials and be able to log on locally to exploit these vulnerabilities.

Severity Rating: Important
Revision Note: V1.0 (March 11, 2014): Bulletin published.
Summary: This security update resolves a privately reported vulnerability in Microsoft Silverlight. The vulnerability could allow security feature bypass if an attacker hosts a website that contains specially crafted Silverlight content that is designed to exploit the vulnerability, and then convinces a user to view the website. In all cases, however, an attacker would have no way to force users to visit a website. Instead, an attacker would have to convince users to visit a 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. It could also be possible to display specially crafted web content by using banner advertisements or by using other methods to deliver web content to affected systems.

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: 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.