CVE-2016-0042 in Windows
Summary
by MITRE
Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 mishandle DLL loading, which allows local users to gain privileges via a crafted application, aka "Windows DLL Loading Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 07/07/2022
The vulnerability identified as CVE-2016-0042 represents a critical privilege escalation flaw in multiple Microsoft Windows operating systems including Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511. This issue stems from improper handling of dynamic link library (DLL) loading mechanisms within the Windows operating system, creating a pathway for local attackers to elevate their privileges from standard user level to system level access. The vulnerability specifically exploits the way Windows resolves and loads DLL files during application execution, allowing malicious actors to manipulate this process and execute arbitrary code with elevated privileges.
The technical root cause of this vulnerability lies in the Windows DLL loading order and search path resolution mechanism. When an application attempts to load a DLL, Windows follows a specific search order that includes the current working directory, system directories, and other locations in a predetermined sequence. The flaw occurs when Windows fails to properly validate or restrict the DLL search path, allowing an attacker to place a malicious DLL file in a location that Windows will prioritize during the loading process. This behavior aligns with CWE-427, which describes uncontrolled search path evaluation, and specifically relates to CWE-787, representing out-of-bounds write conditions that can occur when improper DLL loading leads to memory corruption. The vulnerability enables attackers to exploit this weakness by crafting a malicious application that, when executed, causes the system to load a specially crafted DLL from an attacker-controlled location instead of the legitimate system DLL.
The operational impact of CVE-2016-0042 is severe and far-reaching, as it allows local users to achieve privilege escalation without requiring network connectivity or external attack vectors. An attacker with standard user privileges can leverage this vulnerability to execute code with system-level privileges, potentially gaining complete control over the affected system. This capability can be exploited to install malware, modify system files, create new user accounts, disable security features, or exfiltrate sensitive data from the compromised machine. The vulnerability is particularly dangerous because it does not require network access, meaning that even isolated systems can be compromised through local exploitation. Attackers can use this vulnerability as a stepping stone for broader network infiltration, especially in environments where users may have legitimate access to systems but should not possess administrative privileges. The attack surface is extensive given the wide range of affected operating systems, making this vulnerability particularly attractive to threat actors seeking to maximize their impact across multiple platforms.
Mitigation strategies for CVE-2016-0042 should focus on both immediate patching and operational security measures. Microsoft released security updates that address this vulnerability through proper DLL loading validation and search path restrictions. Organizations must ensure all affected systems are promptly updated with the relevant security patches, as this vulnerability is actively exploited in the wild. Additionally, implementing security controls such as application whitelisting, enabling Windows Defender Application Control, and configuring proper file system permissions can help reduce the risk of exploitation. The principle of least privilege should be enforced to limit user access to only necessary applications and directories. Security monitoring should include detection of unusual DLL loading patterns and attempts to place files in system directories. From an ATT&CK framework perspective, this vulnerability maps to T1055 for privilege escalation through dynamic link library injection and T1068 for local privilege escalation. Organizations should also consider implementing endpoint detection and response solutions that can monitor for suspicious DLL loading behavior and alert on potential exploitation attempts. Network segmentation and regular security audits can further reduce the attack surface and limit the potential impact of successful exploitation.