CVE-2010-5174 in Prevx
Summary
by MITRE
** DISPUTED ** Race condition in Prevx 3.0.5.143 on Windows XP allows local users to bypass kernel-mode hook handlers, and execute dangerous code that would otherwise be blocked by a handler but not blocked by signature-based malware detection, via certain user-space memory changes during hook-handler execution, aka an argument-switch attack or a KHOBE attack. NOTE: this issue is disputed by some third parties because it is a flaw in a protection mechanism for situations where a crafted program has already begun to execute.
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Analysis
by VulDB Data Team • 02/19/2019
The vulnerability described in CVE-2010-5174 represents a significant race condition within the Prevx 3.0.5.143 security solution running on Windows XP systems. This flaw exists within the kernel-mode hook handler mechanism that is designed to monitor and block malicious activities at the system level. The race condition occurs during the execution of hook handlers when user-space memory changes are made concurrently, creating a temporal window where the security system's protective mechanisms can be circumvented. This particular vulnerability is classified as a KHOBE (Kernel-mode Hook Obfuscation Exploitation) attack, which specifically targets the timing aspects of kernel-mode security implementations. The issue is particularly concerning because it allows local users to execute code that would normally be blocked by the kernel-mode hook handlers but remains undetected by traditional signature-based malware detection systems.
The technical implementation of this vulnerability stems from the improper synchronization mechanisms within the Prevx security solution's kernel-mode components. During the execution of hook handlers, which are designed to intercept and analyze system calls, the system fails to properly validate memory states when user-space modifications occur simultaneously. This race condition creates a window where malicious code can be injected or modified in such a way that the hook handler processes incorrect or manipulated arguments, effectively bypassing the intended security controls. The attack vector specifically exploits the timing relationship between user-space memory modifications and kernel-mode hook execution, allowing attackers to switch arguments or manipulate memory contents during the critical execution phase. This type of vulnerability falls under CWE-362, which describes race conditions in security-critical contexts where concurrent access to shared resources can lead to security violations.
The operational impact of this vulnerability extends beyond simple bypass of security controls, as it represents a fundamental flaw in the design of the protection mechanism itself. When successfully exploited, local users can execute arbitrary code that would normally be blocked by the kernel-mode hook handlers, effectively neutralizing the security layer that was specifically designed to prevent such activities. The vulnerability is particularly dangerous because it operates at the kernel level, where it can potentially escalate privileges and gain deeper system access. This creates a scenario where the very mechanism designed to protect the system becomes a point of weakness that can be exploited to circumvent multiple layers of security controls. The attack's effectiveness is further amplified by the fact that it bypasses signature-based detection methods, making it particularly difficult to identify through traditional antivirus or endpoint protection solutions. The vulnerability's disputed nature reflects the complexity of determining whether this represents a legitimate security flaw or an unintended consequence of how the protection mechanism interacts with malicious code execution.
Mitigation strategies for CVE-2010-5174 must address both the immediate exploitation vectors and the underlying design issues within the Prevx security solution. The primary recommendation involves implementing proper synchronization mechanisms and memory validation checks during hook handler execution to prevent the race condition from occurring. Security administrators should consider updating to newer versions of the Prevx solution that address these timing issues, as well as implementing additional monitoring and detection capabilities that can identify anomalous behavior patterns associated with such attacks. The solution should also incorporate more robust argument validation and memory integrity checking during kernel-mode operations to prevent argument-switch attacks from succeeding. Organizations should also consider implementing behavioral-based detection systems that can identify suspicious code execution patterns, as signature-based approaches are ineffective against this type of evasion. Additionally, system administrators should ensure that the affected systems are properly patched and that unnecessary local user privileges are restricted to minimize the potential impact of such exploits. This vulnerability highlights the importance of proper concurrency control in security-critical systems and demonstrates the potential for protection mechanisms to be turned against themselves through carefully orchestrated timing attacks.