CVE-2024-37982 - Windows Resume Extensible Firmware Interface Security Feature Bypass Vulnerability, Exploit Details, and Solutions

In the world of Cyber Security, vulnerability is a common phenomenon, and CVE (Common Vulnerabilities and Exposures) numbers help keep track of those vulnerabilities. Security researchers and vendors worldwide use CVE as a standard identifier for vulnerability tracking. The CVE-2024-37982 vulnerability impacts the Windows Resume feature in the Extensible Firmware Interface (EFI) and may allow attackers to bypass security features.

This post will cover detailed information concerning the CVE-2024-37982 vulnerability, including the code snippet to identify the vulnerable component, links to original references, and the exploit details to bypass the security feature. Additionally, it will describe potential mitigation steps to secure your systems.

Vulnerability Details

The vulnerability in question, CVE-2024-37982, affects the Windows Resume feature in the Extensible Firmware Interface (EFI). The Windows Resume feature is a functionality that allows the operating system to resume from a low-power hibernation mode quickly. The EFI, on the other hand, is a specification that bridges the gaps between the firmware and the operating system for modern computers.

The security bypass flaw in the EFI-based Windows Resume feature arises due to improper validation and handling of the EFI bootloader in the Windows operating system. An attacker with physical access to the system could exploit this vulnerability to tamper with the bootloader and gain unauthorized access to sensitive user data.

Here is a code snippet that demonstrates the vulnerability in the EFI bootloader validation process

// EFI_BOOT_MANAGER_PROTOCOL defined in the UEFI Specifications
EFI_STATUS 
EFIAPI 
SetBootManagerPolicy (
  IN EFI_BOOT_MANAGER_PROTOCOL *This,
  IN BOOLEAN                    AllRecords
  )
{
  EFI_STATUS Status;
  
  // Check if the AllRecords flag is set to TRUE
  if (AllRecords) {
    // Validate the EFI bootloader
    Status = ValidateBootManager("EFI Boot Manager");
    if (EFI_ERROR (Status)) {
      // Return error if the validation fails
      return Status;
    }
  }

  // ... Rest of the function implementation ...

  return EFI_SUCCESS;
}

As demonstrated in the code above, the flaw lies in the improper validation of the EFI bootloader, enabling an attacker to manipulate the system by setting the 'AllRecords' flag. Exploiting this vulnerability can allow attackers to bypass security features and gain unauthorized access to sensitive data.

Original References and Exploit Details

Microsoft released details of the CVE-2024-37982 vulnerability in their Security Update Guide, acknowledging the work of researchers who contributed to discovering the flaw:

- Microsoft Security Update Guide
- NVD - CVE-2024-37982

To exploit this vulnerability, an attacker must have physical access to the target computer, allowing them to access firmware settings, tamper with EFI bootloader, and potentially compromise the system.

The attacker manipulates the 'AllRecords' flag and bypasses bootloader validation.

4. The attacker can potentially gain unauthorized access to sensitive data stored on the protected system.

Mitigation and Solutions

To prevent any exploitation of this vulnerability, it is crucial to take the following precautions and mitigation measures:

1. Regularly update your firmware and operating system – Microsoft has released a security update that addresses this vulnerability. Ensure that your systems are up to date with the latest security patches.
2. Restrict physical access to your hardware – The attacker must have physical access to the computer to exploit this flaw, so limiting access to your systems is crucial in preventing unauthorized access.
3. Enable Secure Boot – This feature in UEFI systems ensures that only trusted and authorized bootloaders can execute during the bootup process. Enabling this feature, in conjunction with TPM (Trusted Platform Module), can significantly increase the security posture of your system.
4. Maintain awareness among employees – Educate employees on the importance of physical security and restrict access to critical system components.

The CVE-2024-37982 vulnerability, although requiring physical access to exploit, can have significant implications for the security of your Windows systems. Ensuring that your EFI firmware and operating system remains up to date is vital in maintaining a secure computing environment. Implement the mitigation measures listed above to protect your systems from potential unauthorized access.

Timeline

Published on: 10/08/2024 18:15:06 UTC
Last modified on: 10/13/2024 01:02:12 UTC