CVE-2025-0288: Paragon Backup & Recovery Privilege Escalation

CVE-2025-0288 Overview

CVE-2025-0288 is an arbitrary kernel memory vulnerability affecting multiple Paragon Software products through the biontdrv.sys driver. The vulnerability exists in the memmove function implementation, which fails to validate or sanitize user-controlled input. This lack of input validation allows an attacker with local access to write arbitrary data to kernel memory, ultimately enabling privilege escalation from a low-privileged user to SYSTEM-level access on affected Windows systems.

Critical Impact

Successful exploitation allows local attackers to achieve privilege escalation by writing arbitrary data to kernel memory through the vulnerable biontdrv.sys driver, potentially leading to complete system compromise.

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-2025-0288 published to NVD
• 2025-06-25 - Last updated in NVD database

Technical Details for CVE-2025-0288

Vulnerability Analysis

This vulnerability represents a classic kernel driver security flaw where user-mode input is passed directly to kernel memory operations without proper validation. The biontdrv.sys driver, which is a kernel-mode component used across Paragon Software's Hard Disk Manager product line, implements functionality that relies on the memmove function to copy data between memory regions.

The core issue lies in the driver's failure to implement proper boundary checks and input sanitization before processing user-supplied data. When a user-mode application communicates with the driver through I/O control codes (IOCTLs), the driver accepts memory addresses and size parameters directly from the user without verification. This allows an attacker to specify arbitrary kernel memory addresses as the destination for write operations.

Root Cause

The root cause of CVE-2025-0288 is improper input validation within the biontdrv.sys kernel driver. Specifically, the driver's IOCTL handler passes user-controlled parameters directly to the memmove function without validating that the destination address lies within legitimate and expected memory regions. This violates fundamental secure coding practices for kernel-mode drivers, where all user input must be treated as untrusted and thoroughly validated before use in privileged operations.

The absence of address space layout validation, buffer size checks, and memory region verification creates a write-what-where condition that attackers can leverage to corrupt kernel data structures or inject malicious code into kernel memory space.

Attack Vector

The attack requires local access to the target system with low-level privileges. An attacker can exploit this vulnerability by:

1. Loading or accessing the vulnerable biontdrv.sys driver on a system where Paragon Software products are installed
2. Crafting malicious IOCTL requests containing attacker-controlled memory addresses and data
3. Sending these requests to the driver to achieve arbitrary kernel memory writes
4. Overwriting critical kernel structures such as process tokens, security descriptors, or callback tables
5. Escalating privileges from a standard user account to SYSTEM-level access

Since the driver is Microsoft-signed, it may be present on systems even without explicit Paragon product installation, as attackers could potentially bring their own vulnerable driver (BYOVD attack technique).

The vulnerability can be exploited through crafted IOCTL requests to the biontdrv.sys driver, where user-controlled parameters are passed directly to the memmove function. This allows an attacker to specify arbitrary kernel memory addresses as write destinations, enabling corruption of critical kernel structures. For detailed technical analysis, refer to the CERT Vulnerability Note #726882.

Detection Methods for CVE-2025-0288

Indicators of Compromise

• Presence of biontdrv.sys driver loaded in kernel memory, especially on systems without Paragon products legitimately installed
• Unusual IOCTL activity targeting Paragon driver device objects
• Process token modifications or unexpected privilege elevation events
• Suspicious driver loading events from non-standard locations

Detection Strategies

• Monitor for loading of biontdrv.sys driver using endpoint detection tools and Windows ETW (Event Tracing for Windows)
• Implement kernel callback monitoring to detect suspicious memory manipulation patterns
• Deploy SentinelOne Singularity platform for real-time behavioral detection of privilege escalation attempts
• Configure Windows Defender Application Control (WDAC) or similar tools to block known vulnerable driver versions

Monitoring Recommendations

• Enable Windows Security Event logging for driver loading events (Event ID 7045)
• Configure Sysmon to capture detailed driver load events with hash verification
• Implement continuous monitoring for process integrity violations and token manipulation
• Review systems for unauthorized Paragon Software installations or standalone driver deployments

How to Mitigate CVE-2025-0288

Immediate Actions Required

• Update all Paragon Software products to the latest patched versions immediately
• Audit systems for the presence of vulnerable biontdrv.sys driver versions
• Implement driver blocking policies using WDAC or SentinelOne device control capabilities
• Restrict local user privileges where possible to limit exploitation potential

Patch Information

Paragon Software has released security patches for all affected products in their Hard Disk Manager product line. Administrators should download and apply the latest updates from the Paragon Software Security Patch advisory page. Additional patches and updates can be found at the Paragon Software Support Patches resource.

Workarounds

• If patching is not immediately possible, consider uninstalling affected Paragon Software products until updates can be applied
• Implement application whitelisting to prevent unauthorized driver loading
• Use WDAC policies to explicitly block the vulnerable biontdrv.sys driver by hash
• Restrict local access to systems where Paragon products are installed to minimize attack surface

# Example: Block vulnerable driver using PowerShell (requires WDAC)
# Create a deny rule for the vulnerable biontdrv.sys driver
New-CIPolicy -FilePath ".\BlockParagonDriver.xml" -Level Hash -ScanPath "C:\Windows\System32\drivers\biontdrv.sys" -Deny
# Convert and deploy the policy
ConvertFrom-CIPolicy -XmlFilePath ".\BlockParagonDriver.xml" -BinaryFilePath ".\BlockParagonDriver.p7b"