Microsoft : Security Vulnerabilities, CVEs, Published In April 2011

DNSAPI.dll in the DNS client in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 does not properly process DNS queries, which allows remote attackers to execute arbitrary code via (1) a crafted LLMNR broadcast query or (2) a crafted application, aka "DNS Query Vulnerability."

Microsoft Excel 2002 SP3, Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac obtain a certain length value from an uninitialized memory location, which allows remote attackers to trigger a buffer overflow and execute arbitrary code via a crafted Excel file, aka "Excel Data Initialization Vulnerability."