ms11-020

MS11-020 is a critical security bulletin from Microsoft addressing a vulnerability in the SMB (Server Message Block) protocol that could allow remote code execution. The update, referenced as KB2508429, resolves a privately reported flaw where an attacker could send a specially crafted SMB packet to an affected system. This vulnerability impacts supported editions of Windows Vista and Windows Server 2008. Microsoft recommends applying the security update to mitigate the risk, noting that firewall best practices and default configurations can help protect networks from external attacks. The bulletin was revised on April 27, 2011, to correct replacement information.