CVE-2006-6952 in Personal Firewall
Summary
by MITRE
Computer Associates Host Intrusion Prevention System (HIPS) drivers (1) Core kmxstart.sys 6.5.4.31 and (2) Firewall kmxfw.sys 6.5.4.10 allow local users to gain privileges by using certain privileged IOCTLs to modify callback function pointers.
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Analysis
by VulDB Data Team • 11/29/2018
The Computer Associates Host Intrusion Prevention System represents a comprehensive security solution designed to protect enterprise networks from various cyber threats through host-based monitoring and firewall capabilities. The vulnerability described in CVE-2006-6952 specifically targets the kernel-mode drivers that form the core of this security infrastructure, namely the Core kmxstart.sys driver version 6.5.4.31 and the Firewall kmxfw.sys driver version 6.5.4.10. These drivers operate at the highest privilege level within the Windows operating system, making them critical components for system security. The flaw arises from improper validation of input parameters within privileged ioctl (input/output control) operations that are exposed through the Windows kernel interface. When local users exploit this vulnerability, they can manipulate callback function pointers that are used by the kernel drivers to execute specific security functions, thereby gaining unauthorized elevated privileges. This represents a classic kernel-mode privilege escalation vulnerability that directly undermines the security model of the operating system.
The technical implementation of this vulnerability stems from the lack of proper access control and validation mechanisms within the driver's ioctl handling routines. According to CWE-264, this vulnerability maps to improper privilege management, where the system fails to properly enforce access restrictions on privileged operations. The drivers expose specific ioctl codes that allow modification of function pointers used for callback mechanisms, but they do not validate whether the calling process has sufficient privileges to perform such modifications. This flaw enables a local attacker with standard user privileges to manipulate the kernel's execution flow by redirecting callback functions to malicious code locations. The vulnerability's impact is particularly severe because it operates at the kernel level, allowing attackers to bypass standard operating system security controls and potentially gain SYSTEM-level privileges. The attack vector requires local access to the system, making it less likely to be exploited remotely, but still poses significant risk in environments where local access is possible or where attackers have already established a foothold through other means.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. Once an attacker gains elevated privileges through this vulnerability, they can manipulate the host intrusion prevention system itself, potentially disabling security features or redirecting security events to avoid detection. This creates a sophisticated attack scenario where the attacker can maintain persistence while remaining undetected by the very security mechanisms designed to protect the system. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1068, which describes privilege escalation through local exploitation, and T1566, which covers social engineering attacks that may lead to local access. The vulnerability also demonstrates the principle of least privilege violation, where the system fails to properly restrict access to kernel-level resources, allowing unauthorized modification of critical system components. Organizations utilizing the affected CA HIPS versions face significant risk as this vulnerability can be leveraged to establish persistent backdoors, escalate privileges to SYSTEM level, and potentially compromise the entire security infrastructure.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected drivers to address the privilege escalation flaw. Organizations should ensure that all instances of the CA Host Intrusion Prevention System are updated to versions that properly validate ioctl parameters and implement proper access controls for privileged operations. The recommended approach includes implementing strict driver signing requirements and disabling unnecessary kernel-mode components that expose privileged interfaces. Security administrators should also conduct thorough vulnerability assessments to identify any systems running the vulnerable drivers and apply patches immediately. Additionally, implementing monitoring solutions that can detect anomalous behavior in kernel drivers, such as unexpected callback function pointer modifications, can provide early warning of potential exploitation attempts. The vulnerability highlights the importance of proper kernel-mode security design and the need for regular security audits of system drivers. Organizations should also consider implementing the principle of least privilege at the kernel level, ensuring that only essential components have access to privileged operations and that all such operations are properly validated and authenticated. Regular security training for system administrators and security personnel on kernel-mode vulnerability exploitation techniques can also help in early detection and prevention of similar security incidents.