CVE-2017-11937 in Windows
Summary
by MITRE
The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Windows 7 SP1, Windows 8.1, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, 1709 and Windows Server 2016, Windows Server, version 1709, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to remote code execution. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability".
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Analysis
by VulDB Data Team • 12/12/2019
The Microsoft Malware Protection Engine remote code execution vulnerability represents a critical security flaw that affected multiple Microsoft products including Windows Defender, Forefront Endpoint Protection, and Exchange Server implementations. This vulnerability stems from improper handling of specially crafted files during malware scanning operations, creating a pathway for attackers to execute arbitrary code on affected systems. The flaw specifically impacts Windows 7 SP1, Windows 8.1, Windows RT 8.1, Windows 10 versions 1511, 1607, 1703, and 1709, along with Windows Server 2016 and Windows Server version 1709, making it one of the most widespread malware protection engine vulnerabilities in recent history. The vulnerability operates at the core of Microsoft's anti-malware scanning functionality, where legitimate scanning operations become vectors for malicious exploitation.
The technical implementation of this vulnerability involves the Malware Protection Engine's failure to properly validate file structures when processing potentially malicious content. When the engine encounters specially crafted files, it attempts to parse and analyze these inputs without adequate sanitization, leading to buffer overflows or memory corruption conditions that attackers can leverage to execute code. This flaw aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability demonstrates characteristics consistent with memory corruption vulnerabilities that enable privilege escalation and remote code execution through carefully constructed input data.
The operational impact of CVE-2017-11937 extends far beyond individual system compromise, as it affects enterprise environments where Microsoft Defender and Forefront Endpoint Protection are widely deployed. Organizations running affected versions of Windows and Exchange Server face significant risk of unauthorized access and potential lateral movement within their networks. Attackers can exploit this vulnerability by delivering malicious files that trigger the vulnerable scanning engine, potentially bypassing traditional security controls and gaining persistent access to target systems. The vulnerability's remote execution capability means that attackers do not need physical access to systems, making it particularly dangerous in environments where automated scanning processes are enabled. This vulnerability directly maps to ATT&CK technique T1059.007 for command and script interpreter, and T1078 for valid accounts, as exploitation often involves leveraging legitimate system processes to execute malicious code.
Mitigation strategies for this vulnerability require immediate patch deployment through Microsoft's security updates, specifically targeting the Malware Protection Engine components. Organizations should also implement network segmentation and monitoring to detect suspicious scanning activities, as well as maintain offline backups of critical systems to prevent complete compromise. The vulnerability highlights the importance of proper input validation and the need for security testing of core system components, particularly those involved in automated security scanning operations. System administrators must also consider implementing additional security controls such as application whitelisting and runtime application control to prevent exploitation of similar vulnerabilities in the future, as this flaw demonstrates how core security components can become attack vectors themselves.