CVE-2008-3761 in Workstation
Summary
by MITRE
hcmon.sys in VMware Workstation 6.5.1 and earlier, VMware Player 2.5.1 and earlier, VMware ACE 2.5.1 and earlier, and VMware Server 1.0.x before 1.0.9 build 156507 and 2.0.x before 2.0.1 build 156745 uses the METHOD_NEITHER communication method for IOCTLs, which allows local users to cause a denial of service via a crafted IOCTL request.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/12/2024
The vulnerability described in CVE-2008-3761 affects VMware's hypervisor components, specifically the hcmon.sys kernel driver used in various VMware products including Workstation, Player, ACE, and Server. This flaw resides in the driver's implementation of IOCTL (Input/Output Control) communication mechanisms, which are fundamental to Windows kernel-mode drivers that facilitate communication between user-mode applications and kernel-mode components. The hcmon.sys driver serves as a monitoring component that tracks virtual machine activities and system events, making it a critical element in VMware's virtualization infrastructure.
The technical flaw stems from the driver's use of METHOD_NEITHER communication method for handling IOCTL requests, which represents a significant deviation from secure driver development practices. In Windows kernel-mode driver development, there are four primary communication methods for IOCTL handling: METHOD_BUFFERED, METHOD_IN_DIRECT, METHOD_OUT_DIRECT, and METHOD_NEITHER. METHOD_NEITHER is specifically designed for cases where the driver itself allocates and manages the memory for input and output data buffers, bypassing the normal Windows kernel buffer management. While this method can provide performance benefits, it introduces critical security risks when not properly implemented, as the driver must manually validate all input data and handle memory management without kernel assistance.
This vulnerability creates a local privilege escalation path that can result in system instability and denial of service conditions. When a local attacker crafts a malicious IOCTL request and sends it to the vulnerable hcmon.sys driver, the driver's improper handling of the METHOD_NEITHER communication method can lead to memory corruption, system crashes, or complete system hangs. The flaw is particularly dangerous because it operates at the kernel level, where malicious code can potentially escalate privileges or disrupt critical system functions. The vulnerability affects multiple VMware products across different versions, indicating it was a widespread issue that persisted for several releases and likely impacted numerous enterprise and individual users running VMware virtualization software.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a fundamental security weakness in VMware's kernel-mode driver implementation. System administrators and security professionals must consider this vulnerability as part of their overall security posture when managing virtualized environments, particularly in scenarios where local user access is possible or where the virtualization platform is used in security-sensitive contexts. The vulnerability's presence in both VMware Workstation and Server products indicates it could affect both desktop virtualization and server virtualization deployments, potentially impacting organizations that rely on VMware for their virtual infrastructure. Organizations should prioritize patching this vulnerability as it represents a potential vector for system compromise and service disruption.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow conditions, as the improper handling of METHOD_NEITHER communication can lead to memory corruption scenarios. From an ATT&CK framework perspective, this vulnerability maps to T1068, which involves the exploitation of legitimate credentials and system access, as local users could leverage this flaw to gain elevated privileges or cause system instability. Additionally, the vulnerability relates to T1499, which covers network disruption and service denial attacks, as the denial of service conditions can impact system availability. The recommended mitigation strategy involves applying the appropriate VMware patches that address the IOCTL handling in the hcmon.sys driver, ensuring that all affected VMware products are updated to versions that properly implement the communication methods for IOCTL requests. Organizations should also consider implementing additional monitoring and access controls to limit local user privileges and reduce the potential impact of such vulnerabilities in their virtualized environments.