CVE-2025-0289: Paragon Backup & Recovery Privilege Escalation

CVE-2025-0289 Overview

CVE-2025-0289 is a high-severity insecure kernel resource access vulnerability affecting multiple Paragon Software products. The vulnerability exists in the kernel-mode driver (Biontdrv.sys) which fails to properly validate the MappedSystemVa pointer before passing it to HalReturnToFirmware. This lack of input validation allows an attacker with local access to potentially compromise the system service and gain elevated privileges.

Critical Impact

Attackers with local access can exploit this vulnerability to achieve high-impact compromise of system confidentiality, integrity, and availability through improper kernel resource handling.

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-2025-0289 published to NVD
• 2025-06-25 - Last updated in NVD database

Technical Details for CVE-2025-0289

Vulnerability Analysis

This vulnerability represents a classic driver vulnerability pattern where insufficient input validation at the kernel level creates a security gap. The Biontdrv.sys driver, used across multiple Paragon Software disk management products, accepts a MappedSystemVa pointer from user-controlled input without adequate verification before invoking the HalReturnToFirmware Hardware Abstraction Layer (HAL) function.

The local attack vector requires an attacker to have existing access to the target system, though no user interaction is required for exploitation. The potential impact is significant, as successful exploitation could lead to complete compromise of system confidentiality, integrity, and availability through kernel-level access.

Root Cause

The root cause of CVE-2025-0289 lies in the driver's failure to implement proper pointer validation mechanisms. When the kernel driver receives the MappedSystemVa pointer, it should verify that the pointer references valid, expected memory regions before using it in privileged operations. The absence of this validation check allows potentially malicious or invalid pointer values to be passed directly to HalReturnToFirmware, a function that operates at a highly privileged level within the Windows kernel.

This represents a broader class of driver vulnerabilities where trust boundaries between user-mode and kernel-mode code are not properly enforced, allowing user-supplied data to influence kernel operations without adequate scrutiny.

Attack Vector

The attack requires local access to the target system with low privileges. An attacker could craft a malicious request to the vulnerable Paragon driver, supplying a specially crafted MappedSystemVa pointer value. When the driver processes this request without validation and passes the pointer to HalReturnToFirmware, it can lead to unintended behavior including service compromise, privilege escalation, or system instability.

The attack does not require any user interaction beyond the attacker's initial local access, making it particularly dangerous in multi-user environments or scenarios where attackers have obtained limited access through other means.

Detection Methods for CVE-2025-0289

Indicators of Compromise

• Unexpected crashes or blue screens (BSODs) related to Biontdrv.sys driver operations
• Unusual process activity interacting with Paragon Software driver interfaces
• Evidence of privilege escalation attempts following legitimate low-privilege user sessions
• Anomalous IOCTL (I/O Control) calls to Paragon kernel drivers

Detection Strategies

• Monitor for suspicious DeviceIoControl calls targeting Paragon driver device objects
• Implement driver integrity monitoring to detect tampering with Biontdrv.sys
• Deploy endpoint detection rules to flag unusual kernel driver interaction patterns
• Audit system logs for driver loading events and associated user context

Monitoring Recommendations

• Enable Windows Driver Verifier on systems with Paragon products to detect driver anomalies
• Configure security event logging for driver installation and modification events
• Implement process monitoring for applications making kernel-mode calls to disk management drivers
• Review system stability reports for driver-related crashes that may indicate exploitation attempts

How to Mitigate CVE-2025-0289

Immediate Actions Required

• Apply the security patch provided by Paragon Software for all affected products immediately
• Inventory all systems with Paragon disk management products installed
• Restrict local access to systems running vulnerable Paragon software until patched
• Consider temporarily disabling or uninstalling affected Paragon products on critical systems until patches can be applied

Patch Information

Paragon Software has released a security patch addressing CVE-2025-0289 for all products in the Hard Disk Manager product line. The patch specifically addresses the Biontdrv.sys driver vulnerability. Administrators should review the Paragon Security Patch Announcement for detailed patching instructions.

Additional technical information is available through CERT Vulnerability ID #726882 and the Paragon Support Patches page.

Workarounds

• Limit local access to systems running Paragon Software products to trusted users only
• Implement application whitelisting to prevent unauthorized applications from interacting with Paragon drivers
• Apply the principle of least privilege to reduce the impact of potential exploitation
• Monitor and audit all local user activities on systems with vulnerable Paragon software