Microsoft April2011 Patch Tuesday Released.

Microsoft has released 17 security bulletins to address publicly disclosed 64 vulnerabilities.Nine bulletins are critical, with all carrying the risk of remote code execution. The remaining eight are ranked important; six of these enable remote code execution, one allows privilege escalation, and the last can lead to information disclosure.
The vulnerabilities affect Microsoft Windows, Microsoft Office, Internet Explorer, Visual Studio, .NET Framework and GDI+.

The following vulnerabilities has rated “Critical”:

MS11-018 – Cumulative Security Update for Internet Explorer (2497640)
MS11-019 – Vulnerabilities in SMB Client Could Allow Remote Code Execution (2511455)
MS11-020 – Vulnerability in SMB Server Could Allow Remote Code Execution (2508429)
MS11-027 – Cumulative Security Update of ActiveX Kill Bits (2508272)
MS11-028 – Vulnerability in .NET Framework Could Allow Remote Code Execution (2484015)
MS11-029 – Vulnerability in GDI+ Could Allow Remote Code Execution (2489979)
MS11-030 – Vulnerability in DNS Resolution Could Allow Remote Code Execution (2509553)
MS11-031 – Vulnerability in JScript and VBScript Scripting Engines Could Allow Remote Code Execution (2514666)
MS11-032 – Vulnerability in the OpenType Compact Font Format (CFF) Driver Could Allow Remote Code Execution (2507618)

The following vulnerabilities has rated “Important”:

MS11-021 – Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution (2489279)
MS11-022 – Vulnerabilities in Microsoft PowerPoint Could Allow Remote Code Execution (2489283)
MS11-023 – Vulnerabilities in Microsoft Office Could Allow Remote Code Execution (2489293)
MS11-024 – Vulnerability in Windows Fax Cover Page Editor Could Allow Remote Code Execution (2527308)
MS11-025 – Vulnerability in Microsoft Foundation Class (MFC) Library Could Allow Remote Code Execution (2500212)
MS11-026 – Vulnerability in MHTML Could Allow Information Disclosure (2503658)
MS11-033 – Vulnerability in WordPad Text Converters Could Allow Remote Code Execution (2485663)
MS11-034 – Vulnerabilities in Windows Kernel-Mode Drivers Could Allow Elevation of Privilege (2506223)

According to Microsoft’s TechNet blog, there are three top priority bulletins, all rated Critical: MS11-020 (SMB Server), MS11-019 (SMB Client) and MS11-018 (Internet Explorer).

MS11-018 (Internet Explorer)-This security bulletin resolves four privately reported vulnerabilities and one publicly disclosed vulnerability in Internet Explorer. This security update is rated Critical for Internet Explorer 6, Internet Explorer 7, and Internet Explorer 8 on Windows clients; and Moderate for Internet Explorer 6, Internet Explorer 7, and Internet Explorer 8 on Windows servers. Internet Explorer 9 is not affected by the vulnerabilities.

MS11-019 (SMB Client)-This security bulletin resolves one publicly disclosed vulnerability and one privately reported vulnerability in Microsoft Windows. The vulnerabilities could allow remote code execution if an attacker sent a specially crafted SMB response to a client-initiated SMB request. To exploit these vulnerabilities, an attacker must convince the user to initiate an SMB connection to a specially crafted SMB server.

MS11-020 (SMB Server)-This security bulletin resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if an attacker created a specially crafted SMB packet and sent the packet to an affected system. Firewall best practices and standard default firewall configurations can help protect networks from attacks originating outside the enterprise perimeter that would attempt to exploit these vulnerabilities.

For detailed information of all the bulletins and the corresponding vulnerabilities addressed, please visit,

https://www.microsoft.com/technet/security/bulletin/ms11-apr.mspx

We will recommend users to set Windows Update in Install updates automatically mode. So the important patches get applied automatically.