Severity Rating: Important
Revision Note: V1.0 (May 12, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow information disclosure when Secure Channel (Schannel) allows the use of a weak Diffie-Hellman ephemeral (DFE) key length of 512 bits in an encrypted TLS session. Allowing 512-bit DHE keys makes DHE key exchanges weak and vulnerable to various attacks. A server needs to support 512-bit DHE key lengths for an attack to be successful; the minimum allowable DHE key length in default configurations of Windows servers is 1024 bits.

Severity Rating: Important
Revision Note: V1.0 (May 12, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Windows Service Control Manager (SCM), which is caused when SCM improperly verifies impersonation levels. The vulnerability could allow elevation of privilege if an attacker can first log on to the system and then run a specially crafted application designed to increase privileges.

Severity Rating: Critical
Revision Note: V1.0 (May 12, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. 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: Important
Revision Note: V1.0 (May 12, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Silverlight. The vulnerability could allow elevation of privilege if a specially crafted Silverlight application is run on an affected system. To exploit the vulnerability an attacker would first have to log on to the system or convince a logged on user to execute the specially crafted application.

Severity Rating: Important
Revision Note: V1.0 (May 12, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of 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 (May 12, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow remote code execution if a user opens a specially crafted Journal file. 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.

Revision Note: V1.0 (May 12, 2015): Bulletin Summary published.
Summary: This bulletin summary lists security bulletins released for May 2015.

Revision Note: V1.0 (May 1, 2015): V1.0 (May 1, 2015): Advisory published.
Summary: Microsoft is offering the Local Administrator Password Solution (LAPS) that provides a solution to the issue of using a common local account with an identical password on every computer in a domain. LAPS resolves this issue by setting a different, random password for the common local administrator account on every computer in the domain. Domain administrators using the solution can determine which users, such as helpdesk administrators, are authorized to read passwords.

Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow elevation of privilege if an attacker logs on to the system and runs a specially crafted application.

Severity Rating: Important
Revision Note: V1.0 (April 14, 2015): Bulletin published.
Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow denial of service if an authenticated attacker runs a specially crafted application in a virtual machine (VM) session. Note that the denial of service does not allow an attacker to execute code or elevate user rights on other VMs running on the Hyper-V host; however, it could cause other VMs on the host to not be manageable in Virtual Machine Manager.