CVE-2008-0779 in FortiClient Host Security
Summary
by MITRE
The fortimon.sys device driver in Fortinet FortiClient Host Security 3.0 MR5 Patch 3 and earlier does not properly initialize its DeviceExtension, which allows local users to access kernel memory and execute arbitrary code via a crafted request.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/06/2019
The vulnerability identified as CVE-2008-0779 represents a critical kernel-mode device driver flaw within Fortinet FortiClient Host Security software version 3.0 MR5 Patch 3 and earlier releases. This issue stems from improper initialization of the DeviceExtension structure within the fortimon.sys kernel driver, creating a dangerous condition that enables local privilege escalation and arbitrary code execution. The flaw exists at the core level of the operating system's security architecture, where device drivers operate with elevated privileges and direct access to system memory.
The technical root cause of this vulnerability lies in the insufficient validation and initialization processes within the kernel driver's DeviceExtension component. When the fortimon.sys driver handles incoming requests from user-mode applications, it fails to properly establish the necessary memory structures and access controls that should normally be in place during driver initialization. This incomplete initialization creates memory access vulnerabilities that allow local attackers to craft malicious requests that can manipulate kernel memory directly. The DeviceExtension structure, which typically manages driver-specific data and state information, remains improperly configured, enabling attackers to exploit memory layout weaknesses and bypass normal kernel security mechanisms.
From an operational perspective, this vulnerability presents a severe risk to systems running affected FortiClient versions as it allows local users to escalate their privileges from standard user level to kernel level execution. The ability to execute arbitrary code in kernel space means attackers can bypass all standard operating system security controls, including user access controls, memory protection mechanisms, and application sandboxing. This creates a pathway for complete system compromise where attackers can install rootkits, modify system files, access encrypted data, and maintain persistent access to the compromised machine. The vulnerability is particularly dangerous because it requires no network connectivity or remote exploitation, making it exploitable through local system access alone.
The impact of this vulnerability aligns with CWE-665 improper initialization of resources, which falls under the broader category of improper initialization flaws that can lead to memory corruption and privilege escalation attacks. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged to achieve initial access and persistence within a compromised system. Security researchers have identified this as a classic example of a kernel-mode exploit that can be used to bypass modern security controls such as data execution prevention, address space layout randomization, and kernel address space layout randomization. The vulnerability demonstrates how device driver flaws can create fundamental security weaknesses that undermine the entire operating system security model.
Organizations affected by this vulnerability should immediately implement mitigation strategies including patching to the latest FortiClient Host Security versions that contain proper DeviceExtension initialization code. System administrators should also consider implementing additional security measures such as disabling unnecessary device drivers, applying kernel patch management procedures, and monitoring for suspicious kernel-mode activities. The vulnerability highlights the importance of proper driver development practices and the critical need for thorough security testing of kernel-mode components before deployment in production environments. Regular security assessments and vulnerability scanning should include kernel driver evaluation to identify similar initialization flaws that could potentially create similar security risks.