CVE-2016-3302 in Windows
Summary
by MITRE
Microsoft Windows 8.1, Windows Server 2012 R2, Windows RT 8.1, and Windows 10 Gold, 1511, and 1607, when the lock screen is enabled, do not properly restrict the loading of web content, which allows physically proximate attackers to execute arbitrary code via a (1) crafted Wi-Fi access point or (2) crafted mobile-broadband device, aka "Windows Lock Screen Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 10/07/2024
This vulnerability exists in multiple Microsoft Windows operating systems including Windows 8.1, Windows Server 2012 R2, Windows RT 8.1, and various Windows 10 versions. The flaw resides in how the lock screen handles web content loading, creating a security boundary that can be exploited by attackers who are physically close to the target device. The vulnerability is categorized under CWE-264, which deals with permissions, privileges, and access controls, specifically highlighting inadequate restrictions on resource loading. This issue represents a critical elevation of privilege vulnerability as it allows attackers to execute arbitrary code on the affected systems.
The technical exploitation occurs through two primary vectors: crafted Wi-Fi access points and crafted mobile-broadband devices. When a device with an enabled lock screen connects to a malicious Wi-Fi network or mobile-broadband device, the system's web content loading mechanism fails to properly validate or restrict the content being loaded. This improper restriction allows malicious actors to inject and execute arbitrary code with elevated privileges, effectively bypassing the normal security boundaries that should protect the system when locked. The vulnerability specifically targets the lock screen functionality, which is designed to provide a user interface while the system is in a locked state, but fails to properly isolate potentially dangerous web content.
The operational impact of this vulnerability is significant as it enables attackers to gain unauthorized code execution capabilities without requiring remote access or complex attack vectors. The proximity requirement means that attackers must be physically near the target device, which limits the attack scope but does not eliminate the threat. This vulnerability can be particularly dangerous in enterprise environments where physical security controls may be insufficient, allowing attackers to compromise devices that are otherwise protected by standard network security measures. The attack can result in complete system compromise, data theft, or further lateral movement within a network. According to ATT&CK framework, this vulnerability maps to T1068, which covers 'Exploitation for Privilege Escalation,' and T1059, which covers 'Command and Scripting Interpreter,' as attackers can execute arbitrary commands and scripts through this vector.
Mitigation strategies should focus on disabling lock screen web content loading functionality, which can be achieved through group policy settings or registry modifications. Microsoft released security updates that address this vulnerability, and organizations should ensure all affected systems are patched promptly. Network administrators should consider implementing additional physical security measures such as device encryption, secure lock screen configurations, and monitoring for suspicious network connections. The vulnerability also highlights the importance of proper input validation and content restriction mechanisms in operating system components, particularly those that handle user interface elements and network communications. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such attacks, as the vulnerability can be leveraged for broader network compromise once initial access is gained.