CVE-2007-4223 in Sysinternals
Summary
by MITRE
Dbgv.sys in Microsoft Sysinternals DebugView before 4.72 provides an unspecified mechanism for copying data into kernel memory, which allows local users to gain privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 04/23/2017
The vulnerability identified as CVE-2007-4223 resides within the Dbgv.sys kernel driver component of Microsoft Sysinternals DebugView utility versions prior to 4.72. This driver operates at the kernel level and provides debugging capabilities for system processes, making it a critical component in the Windows operating system architecture. The vulnerability specifically involves an unspecified mechanism that facilitates copying data into kernel memory, which represents a fundamental security flaw in how the driver handles memory operations. This type of flaw falls under the category of kernel-mode memory corruption vulnerabilities that can be exploited by local attackers to escalate privileges from standard user level to system level access.
The technical nature of this vulnerability stems from improper validation and handling of data transfers between user-mode applications and kernel-mode drivers. When DebugView is installed and running, the Dbgv.sys driver maintains a kernel-mode component that accepts data from user applications for debugging purposes. The unspecified mechanism for copying data into kernel memory suggests that the driver lacks proper bounds checking, input validation, or memory protection mechanisms that would normally prevent unauthorized data manipulation within kernel space. This creates a potential for buffer overflow conditions or other memory corruption scenarios that can be exploited by malicious local users to execute arbitrary code with elevated privileges.
The operational impact of CVE-2007-4223 is significant as it enables local privilege escalation attacks that can result in complete system compromise. An attacker with standard user access can leverage this vulnerability to gain kernel-level privileges, effectively bypassing Windows security controls and gaining unrestricted access to system resources, files, and processes. This vulnerability directly violates the principle of least privilege and undermines the security model of Windows operating systems by allowing local users to elevate their privileges without proper authentication or authorization. The exploitability of this vulnerability is enhanced by the fact that it requires no network connectivity and can be executed locally on the target system, making it particularly dangerous in environments where users have access to local system resources.
The vulnerability aligns with CWE-121, which describes the weakness of stack-based buffer overflow conditions, and potentially CWE-122, which addresses heap-based buffer overflow scenarios. From an ATT&CK framework perspective, this vulnerability maps to T1068, which covers 'Exploitation for Privilege Escalation', and T1547.001, which covers 'Registry Run Keys / Startup Folder'. The attack pattern involves local exploitation through kernel-mode privilege escalation, where an attacker can manipulate the vulnerable driver to execute malicious code with system-level privileges. Organizations should implement immediate mitigations including updating to DebugView version 4.72 or later, which addresses the kernel memory handling issues, and applying the principle of least privilege by limiting local user access to systems running vulnerable versions of the utility. Additionally, system administrators should monitor for unauthorized installations of Sysinternals utilities and ensure proper access controls are enforced to prevent exploitation of this vulnerability.
The broader implications of this vulnerability highlight the importance of kernel-mode security in operating system design and the need for comprehensive security testing of driver components. The vulnerability demonstrates how seemingly legitimate debugging tools can contain security flaws that can be exploited by malicious actors, emphasizing the critical nature of driver security in modern computing environments. Organizations should maintain current security patches for all system components, including third-party utilities, and conduct regular security assessments to identify and remediate similar vulnerabilities that could potentially allow privilege escalation attacks. The incident also underscores the necessity of proper code review and security testing practices for kernel-mode components to prevent memory corruption vulnerabilities that can lead to complete system compromise.