CVE-2022-31693: Exploring the Denial-of-Service Vulnerability in VMware Tools for Windows

CVE-2022-31693 is a troubling denial-of-service (DoS) vulnerability found in VMware Tools for Windows versions 12.x.y prior to 12.1.5, 11.x.y, and 10.x.y. In this long read, we will examine this vulnerability in detail, including analyzing code snippets, exploring links to original sources, and discussing the exploitation process. The goal of this article is to raise awareness of this security issue and encourage users to properly protect their systems.

I. Overview of the vulnerability

VMware Tools for Windows encompasses several crucial utilities and drivers that allow for enhanced VM functionalities, one of which is the VM3DMP driver that is currently harboring a denial-of-service vulnerability. By exploiting this vulnerability, a malicious actor with local user access to the Windows guest operating system (OS) can trigger a PANIC in the VM3DMP driver, which in turn leads to a denial-of-service condition in the guest OS.

II. Technical breakdown of the vulnerability

The vulnerability is rooted in the VM3DMP driver’s improper handling of specific I/O requests, which consequently causes the driver to crash.

Here is a code snippet that provides a simplified example of this vulnerability

NTSTATUS SomeFunction(PVOID pDeviceExtension, PIRP pIrp)
{
    PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(pIrp);
    ULONG IoControlCode = pIrpStack->Parameters.DeviceIoControl.IoControlCode;

    switch (IoControlCode)
    {
    case IOCTL_TRIGGER_PANIC:
        // Vulnerable code
        DoSomethingBad();
        break;

    default:
        // Regular non-vulnerable code
        break;
    }

    // Rest of the code
}

As shown above, the function processes different I/O requests by a given control code. The vulnerable case statement (IOCTL_TRIGGER_PANIC) contains problematic code that causes the VM3DMP driver to crash. Since the crashing of the driver leads to a denial-of-service condition, it is crucial to address and rectify this vulnerability.

III. Exploitation Process

To exploit the vulnerability, a malicious actor must first obtain local user privileges in the Windows guest OS running VMware Tools. Next, the attacker can craft specific I/O requests that trigger a PANIC in the VM3DMP driver, causing it to crash and ultimately leading to a denial-of-service condition in the guest OS.

Considering the impact of a successful exploitation, organizations should take immediate steps to protect their systems against this vulnerability.

IV. Mitigation and solutions

To resolve the CVE-2022-31693 vulnerability, ensure that your VMware Tools for Windows is updated to version 12.1.5 or later. Additionally, organizations should enforce strict access control policies for users with access to their Windows guest OS environments to minimize the risk of exploitation.

V. Original references and sources

1. VMware Security Advisory: VMSA-2022-0003
2. Mitre CVE Details: CVE-2022-31693
3. NVD Details: CVE-2022-31693

Conclusion

CVE-2022-31693 represents a severe security threat within VMware Tools for Windows, allowing attackers with local access to exploit a denial-of-service vulnerability that ultimately disrupts the guest OS’s capabilities. To safeguard your systems, always keep your software up-to-date and establish strong access control policies.

Timeline

Published on: 06/07/2023 14:15:00 UTC
Last modified on: 06/20/2023 18:13:00 UTC