CVE-2025-0286: Paragon Backup & Recovery RCE Vulnerability

CVE-2025-0286 Overview

CVE-2025-0286 is an arbitrary kernel memory write vulnerability affecting multiple Paragon Software products. The flaw exists within the biontdrv.sys kernel driver and stems from improper validation of user-supplied data length. This vulnerability allows an attacker with local access to execute arbitrary code at the kernel level, potentially leading to complete system compromise.

The vulnerability is classified under CWE-1284 (Improper Validation of Specified Quantity in Input), indicating that the driver fails to properly validate the size or length parameters provided by user-mode applications before performing memory operations in kernel space.

Critical Impact

Successful exploitation allows local attackers to achieve arbitrary kernel memory writes, enabling code execution with SYSTEM privileges, bypassing security controls, and potentially disabling endpoint protection mechanisms.

Affected Products

• Paragon Backup & Recovery
• Paragon Disk Wiper
• Paragon Drive Copy
• Paragon Hard Disk Manager
• Paragon Migrate OS to SSD
• Paragon Partition Manager

Discovery Timeline

• 2025-03-03 - CVE-2025-0286 published to NVD
• 2025-06-25 - Last updated in NVD database

Technical Details for CVE-2025-0286

Vulnerability Analysis

This vulnerability resides in the biontdrv.sys kernel-mode driver, which is a shared component across Paragon Software's Hard Disk Manager product line. The driver handles disk management operations and exposes IOCTL (I/O Control) interfaces to user-mode applications.

The core issue is an improper validation of specified quantity in input (CWE-1284), where the driver accepts user-supplied length values without adequate bounds checking. When processing certain IOCTL requests, the driver uses these unchecked length values to determine memory write operations, allowing an attacker to write arbitrary data to arbitrary kernel memory locations.

This class of vulnerability is particularly dangerous because kernel-mode drivers operate with the highest privilege level on Windows systems. An arbitrary kernel memory write primitive can be weaponized to:

• Overwrite kernel data structures to escalate privileges
• Disable security software and kernel-mode protections
• Install rootkits or other persistent malware
• Bypass Driver Signature Enforcement (DSE)

Root Cause

The root cause of CVE-2025-0286 is the failure of the biontdrv.sys driver to properly validate the length of user-supplied data before using it in kernel memory operations. When user-mode applications communicate with kernel drivers through IOCTL calls, they provide input buffers with associated length fields. The vulnerable driver trusts these length values without performing adequate validation, allowing specially crafted requests to specify write operations that extend beyond intended boundaries.

This type of vulnerability typically occurs in IOCTL handlers that process METHOD_NEITHER or METHOD_BUFFERED I/O requests without implementing proper input validation checks. The driver should validate that:

• The input buffer length matches expected parameters
• The output buffer is appropriately sized
• Memory addresses fall within valid ranges
• No integer overflow conditions can occur in size calculations

Attack Vector

The attack vector for CVE-2025-0286 is local, requiring an attacker to have some level of access to the target system. The exploitation scenario typically involves:

1. Initial Access: The attacker gains local access to a system running one of the affected Paragon Software products
2. Driver Communication: The attacker opens a handle to the biontdrv.sys driver device object
3. Crafted IOCTL: A malicious IOCTL request is sent with manipulated length parameters
4. Kernel Write Primitive: The driver processes the request and performs an arbitrary kernel memory write based on attacker-controlled values
5. Privilege Escalation: The write primitive is leveraged to modify kernel structures, enabling SYSTEM-level code execution

The exploitation does not require user interaction and can be performed with low privileges, making it a significant threat in scenarios where attackers have achieved initial foothold through other means.

Detection Methods for CVE-2025-0286

Indicators of Compromise

• Suspicious IOCTL communications with biontdrv.sys driver from unexpected processes
• Anomalous kernel memory modifications or system instability following driver interactions
• Presence of unsigned or modified versions of biontdrv.sys on the system
• Unexpected privilege escalation events following Paragon software usage

Detection Strategies

• Monitor for unusual DeviceIoControl API calls targeting the Paragon driver device objects
• Implement kernel-mode behavioral analysis to detect arbitrary memory write attempts
• Deploy endpoint detection rules that flag exploitation patterns targeting biontdrv.sys
• Utilize driver load monitoring to identify vulnerable versions of the driver

Monitoring Recommendations

• Enable Windows Security Event logging for driver load events (Event ID 6)
• Configure SIEM rules to correlate driver installation with subsequent privilege escalation
• Implement file integrity monitoring for biontdrv.sys and related Paragon driver files
• Deploy behavioral analytics to detect post-exploitation activities following kernel manipulation

How to Mitigate CVE-2025-0286

Immediate Actions Required

• Identify all systems running affected Paragon Software products across your environment
• Apply the vendor-provided security patch for biontdrv.sys immediately
• Consider temporarily removing or disabling affected Paragon products on critical systems until patching is complete
• Implement application whitelisting to restrict which processes can communicate with kernel drivers

Patch Information

Paragon Software has released a security patch addressing this vulnerability in biontdrv.sys. Administrators should download and apply the latest patches from the Paragon Software Support Patches page. For detailed information about the security update, refer to the Paragon Security Patch Announcement.

Additional information is available in the CERT Vulnerability Report #726882.

Workarounds

• If immediate patching is not possible, consider uninstalling affected Paragon Software products temporarily
• Restrict local access to systems running vulnerable software to minimize attack surface
• Implement strict user access controls and principle of least privilege
• Deploy endpoint protection solutions capable of detecting kernel-level exploitation attempts