CVE-2019-0692 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists due to an integer overflow in Windows Subsystem for Linux, aka 'Windows Subsystem for Linux Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0682, CVE-2019-0689, CVE-2019-0693, CVE-2019-0694.
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Analysis
by VulDB Data Team • 08/01/2023
The vulnerability identified as CVE-2019-0692 represents a critical elevation of privilege flaw within the Windows Subsystem for Linux (WSL) component of Microsoft Windows operating systems. This issue specifically manifests as an integer overflow condition that occurs during the processing of certain system calls or memory operations within the WSL environment. The vulnerability affects Windows 10 versions prior to the security updates released in May 2019, creating a pathway for malicious actors to escalate their privileges from standard user level to administrative access within the Windows operating system. The integer overflow vulnerability stems from improper validation of input parameters that are processed by the WSL subsystem, allowing attackers to manipulate memory boundaries and potentially execute arbitrary code with elevated privileges.
The technical exploitation of this vulnerability involves leveraging the integer overflow condition to corrupt memory structures or manipulate pointer values within the WSL kernel components. This flaw enables attackers to bypass normal access controls and security boundaries that typically separate user processes from system-level operations. According to CWE classification, this vulnerability maps to CWE-190, Integer Overflow or Wraparound, which specifically addresses situations where integer arithmetic results in values that exceed the maximum representable value for the data type. The operational impact of this vulnerability extends beyond the WSL environment itself, as successful exploitation could provide attackers with complete system compromise capabilities. Attackers could potentially use this privilege escalation to install persistent backdoors, modify system files, access sensitive data, or establish command and control channels within the compromised Windows environment.
The security implications of CVE-2019-0692 align with ATT&CK framework techniques categorized under privilege escalation and persistence. Specifically, this vulnerability enables techniques such as T1068 (Local Port Forwarding) and T1059 (Command and Scripting Interpreter) by allowing attackers to execute commands with elevated privileges. The vulnerability's impact is particularly concerning because it affects a core Windows feature that many organizations rely on for development, testing, and compatibility purposes. Organizations running WSL-enabled systems were at risk of complete system compromise, as the vulnerability could be exploited through various attack vectors including malicious software installation, web-based attacks, or even physical access scenarios. The integer overflow condition typically occurs when a 32-bit integer value exceeds its maximum capacity of 2,147,483,647, causing it to wrap around to negative values or zero, which can lead to unpredictable behavior and memory corruption.
Mitigation strategies for CVE-2019-0692 primarily focus on applying the relevant Microsoft security updates that address the integer overflow condition within the WSL subsystem. Organizations should immediately deploy the May 2019 security patches that specifically target this vulnerability, as well as ensure that all Windows 10 systems are kept current with the latest security updates. System administrators should also implement additional security controls such as disabling WSL for users who do not require Linux environment capabilities, monitoring for suspicious process activities, and maintaining network segmentation to limit potential lateral movement. The vulnerability's exploitation requires minimal privileges initially, making it particularly dangerous as attackers can first establish a foothold using lower-privilege accounts and then leverage this flaw for system-wide compromise. Security monitoring should focus on detecting unusual memory access patterns, unexpected privilege escalation events, and unauthorized modifications to system files that may indicate successful exploitation attempts. Organizations should also consider implementing the principle of least privilege for WSL users and regularly audit WSL configurations to ensure that only necessary components are enabled and properly secured.