CVE-2024-49114 - Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability Discovered and How to Mitigate the Risk

Summary: This article aims to provide an in-depth analysis of the recently discovered Windows Cloud Files Mini Filter Driver Elevation of Privilege vulnerability CVE-2024-49114. Throughout this article, we will examine the code snippet in question, understand the exploit details, and learn about the mitigation steps that can be taken to ensure the security of your systems.

Introduction

CVE-2024-49114 is a vulnerability that affects Windows systems using the Cloud Files Mini Filter Driver. This component is used by various cloud storage providers, such as DropBox, OneDrive, and Google Drive, to extend their file system to the user's local environment. The vulnerability has been categorized as an Elevation of Privilege, which means that attackers might exploit this security flaw to gain control over the victim's system and perform unauthorized actions. This article takes a comprehensive look at this vulnerability, its effects, and mitigation strategies.

Code Snippet

The following code snippet represents the vulnerable function found in the Cloud Files Mini Filter Driver:

NTSTATUS
CldFltInstanceSetup (
    _In_ PCFLT_RELATED_OBJECTS FltObjects,
    _In_ FLT_INSTANCE_SETUP_FLAGS Flags,
    _In_ DEVICE_TYPE VolumeDeviceType,
    _In_ FLT_FILESYSTEM_TYPE VolumeFilesystemType
    )
{
    NTSTATUS status = STATUS_SUCCESS;

    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( Flags );
    UNREFERENCED_PARAMETER( VolumeDeviceType );
    UNREFERENCED_PARAMETER( VolumeFilesystemType );

    try {

        if (FlagOn(Flags, FLTFL_INSTANCE_SETUP_NEWLY_MOUNTED_VOLUME)) {
            status = CldFltGetVolumeContext( FltObjects->Volume, NULL );

            if (!NT_SUCCESS( status )) {
                status = STATUS_SUCCESS;
                CldFltSetVolumeContext( FltObjects->Volume,  );
            }
        }

    } except( EXCEPTION_EXECUTE_HANDLER ) {
        status = GetExceptionCode();
    }

    return status;
}

In the code above, the function 'CldFltInstanceSetup' processes input parameters, but does not validate them correctly. This oversight can potentially lead to an attacker triggering unexpected behavior by sending specially crafted input parameters.

Exploit Details

By exploiting this vulnerability, an attacker could potentially use a crafted Windows API call to trigger the Cloud Files Mini Filter Driver function and manipulate the input parameters. Given that the driver runs in a privileged context on the system, the attacker might be able to achieve arbitrary code execution with administrator-level permissions.

To address this vulnerability, the following mitigation steps can and should be taken

1. Apply the Security Update
Microsoft has released a security update that addresses this vulnerability. By installing the update, you can protect your system and reduce the likelihood of successful exploitation of CVE-2024-49114.

Enable User Account Control (UAC)

Ensuring that User Account Control (UAC) is enabled on your system can help in mitigating the potential for an attacker to gain elevated privileges. UAC prompts users for consent when any action requires elevated privileges, making it more challenging for an attacker to abuse this vulnerability without detection.

Consider using alternative cloud file storage solutions

If possible, temporarily switch to alternative cloud file storage solutions that do not rely on the Cloud Files Mini Filter Driver or choose one that is not affected by this vulnerability.

Monitor system logs for suspicious activity

Regularly monitoring system logs can help in identifying any unauthorized activity that might result from the exploitation of this vulnerability. Detection of attempts to exploit CVE-2024-49114 can help prevent a full compromise of your environment.

Educate users about phishing attempts and attachments

Educating users about the risks of phishing attempts and suspicious attachments can help prevent attackers from gaining an initial foothold in the target network, from which they might try to exploit this vulnerability.

Conclusion

CVE-2024-49114 is a critical elevation of privilege vulnerability in the Windows Cloud Files Mini Filter Driver, which can lead to attackers gaining administrator-level access to the victim's system. By applying the security update provided by Microsoft, enabling User Account Control, opting for alternative cloud storage solutions, monitoring system logs, and educating users, you can effectively mitigate the risk posed by this vulnerability and maintain a secure working environment for your organization.

Timeline

Published on: 12/12/2024 02:04:37 UTC
Last modified on: 12/20/2024 07:44:57 UTC