CVE-2008-3431 in xVM VirtualBox
Summary
by MITRE
The VBoxDrvNtDeviceControl function in VBoxDrv.sys in Sun xVM VirtualBox before 1.6.4 uses the METHOD_NEITHER communication method for IOCTLs and does not properly validate a buffer associated with the Irp object, which allows local users to gain privileges by opening the \\.\VBoxDrv device and calling DeviceIoControl to send a crafted kernel address.
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability described in CVE-2008-3431 represents a critical privilege escalation flaw within the Sun xVM VirtualBox virtualization software ecosystem. This issue specifically affects versions prior to 1.6.4 and resides within the VBoxDrv.sys kernel driver component that manages device control operations for the virtualization environment. The vulnerability stems from improper input validation mechanisms that fail to adequately verify buffer parameters associated with the Irp (I/O Request Packet) object during device control operations. The flaw becomes particularly dangerous because it leverages the METHOD_NEITHER communication method, which is inherently risky as it does not automatically validate buffer parameters, leaving the driver susceptible to malformed input manipulation.
The technical implementation of this vulnerability exploits the kernel driver's handling of IOCTL (Input/Output Control) operations through the \.\VBoxDrv device interface. When a local user establishes a connection to this device and invokes DeviceIoControl with a specially crafted kernel address, the VBoxDrvNtDeviceControl function fails to validate the buffer associated with the Irp object. This validation failure creates an opportunity for privilege escalation because the kernel driver does not properly sanitize the input parameters before processing them. The METHOD_NEITHER communication approach exacerbates this issue as it bypasses automatic buffer validation mechanisms that would normally protect against such attacks, requiring explicit validation checks to be implemented by the driver developer.
The operational impact of this vulnerability is severe and directly affects the security model of the virtualization platform. Local users who can access the system can exploit this flaw to elevate their privileges from standard user level to kernel level execution. This privilege escalation allows attackers to bypass normal access controls, potentially enabling them to access sensitive system resources, modify critical system files, or execute arbitrary code with the highest privileges available. The attack vector is particularly concerning because it requires minimal prerequisites - simply having access to the local system and the ability to open the VBoxDrv device interface is sufficient to attempt exploitation. This vulnerability undermines the fundamental security boundaries that virtualization software is designed to maintain between guest operating systems and the host system.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes buffer overflow conditions in stack-based buffers, and represents a classic example of improper input validation leading to privilege escalation. The ATT&CK framework categorizes this as privilege escalation through kernel exploits, specifically falling under the technique of "Exploitation for Privilege Escalation" where adversaries leverage software vulnerabilities to gain elevated system privileges. Organizations running affected versions of VirtualBox face significant risk as this vulnerability can be exploited without requiring network access or remote execution capabilities, making it particularly dangerous in environments where local access is possible. The vulnerability also demonstrates the importance of proper kernel driver security practices and highlights the need for comprehensive input validation even in trusted system components. Mitigation efforts should focus on immediate patching to version 1.6.4 or later, along with implementing additional access controls to limit local user privileges and monitoring for suspicious DeviceIoControl operations against virtualization device interfaces.