CVE-2025-69783: OpenEDR Privilege Escalation Vulnerability

CVE-2025-69783 Overview

A local attacker can bypass OpenEDR's 2.5.1.0 self-defense mechanism by renaming a malicious executable to match a trusted process name (e.g., csrss.exe, edrsvc.exe, edrcon.exe). This allows unauthorized interaction with the OpenEDR kernel driver, granting access to privileged functionality such as configuration changes, process monitoring, and IOCTL communication that should be restricted to trusted components. While this issue alone does not directly grant SYSTEM privileges, it breaks OpenEDR's trust model and enables further exploitation leading to full local privilege escalation.

Critical Impact

This vulnerability undermines the integrity of OpenEDR's security architecture by allowing attackers to impersonate trusted processes, potentially leading to full local privilege escalation on affected systems.

Affected Products

• OpenEDR version 2.5.1.0
• Systems running OpenEDR kernel driver with process name-based trust validation
• Windows environments with OpenEDR endpoint protection deployed

Discovery Timeline

• 2026-03-16 - CVE-2025-69783 published to NVD
• 2026-03-17 - Last updated in NVD database

Technical Details for CVE-2025-69783

Vulnerability Analysis

This vulnerability stems from a fundamental flaw in how OpenEDR validates the trustworthiness of processes attempting to communicate with its kernel driver. The endpoint detection and response solution relies on process name matching to determine whether a process should be granted elevated privileges to interact with the kernel driver's IOCTL interface.

The trust model implementation checks only the executable filename rather than performing robust identity verification such as digital signature validation, file path verification, or cryptographic hash checking. This allows any local user with the ability to create and execute files to simply rename their malicious executable to match one of the trusted process names hardcoded in the driver.

Once an attacker's process is misidentified as trusted, they gain unauthorized access to sensitive kernel driver functionality including configuration modification, process monitoring capabilities, and direct IOCTL communication channels. This breaks the security boundary that OpenEDR relies upon to protect its own integrity and can serve as a stepping stone to full local privilege escalation.

Root Cause

The vulnerability is classified as CWE-250 (Execution with Unnecessary Privileges). The root cause lies in the insufficient validation mechanism used by OpenEDR's kernel driver to authenticate calling processes. By relying solely on executable filename matching without additional verification such as code signing validation, file location checking, or process token verification, the driver cannot distinguish between legitimate OpenEDR components and malicious executables that have been renamed to impersonate them.

Attack Vector

The attack requires local access with low privileges and no user interaction. An attacker with the ability to execute code on the target system can perform the following attack sequence:

1. Create or obtain a malicious executable designed to interact with the OpenEDR kernel driver
2. Rename the executable to match a trusted process name such as csrss.exe, edrsvc.exe, or edrcon.exe
3. Execute the renamed malicious process from any location on the filesystem
4. The OpenEDR kernel driver identifies the process as trusted based on name matching
5. The attacker's process gains unauthorized access to privileged IOCTL interfaces
6. Leverage the privileged access to modify OpenEDR configuration, disable protections, or escalate privileges

The vulnerability affects the local attack surface and requires an attacker to already have code execution capabilities on the target system. However, the ability to bypass EDR self-defense mechanisms significantly amplifies the impact of initial access, as it allows attackers to neutralize endpoint protection before conducting further malicious activities.

Detection Methods for CVE-2025-69783

Indicators of Compromise

• Processes named csrss.exe, edrsvc.exe, or edrcon.exe executing from non-standard directories (outside %SystemRoot%\System32 or OpenEDR installation paths)
• Unsigned executables with names matching OpenEDR trusted process names
• Unexpected IOCTL communication with the OpenEDR kernel driver from suspicious process paths
• Configuration changes to OpenEDR settings without administrative action

Detection Strategies

• Monitor process creation events for executables with trusted EDR process names spawning from unusual locations
• Implement file integrity monitoring on known OpenEDR installation directories
• Alert on processes communicating with the OpenEDR driver that lack valid digital signatures
• Cross-reference process names against expected file paths using SIEM correlation rules

Monitoring Recommendations

• Enable detailed process auditing including command line logging and parent process tracking
• Configure alerts for any modifications to OpenEDR configuration files or registry settings
• Monitor kernel driver communication patterns for anomalous IOCTL requests
• Review security logs for process name spoofing attempts targeting known trusted executable names

How to Mitigate CVE-2025-69783

Immediate Actions Required

• Review systems running OpenEDR 2.5.1.0 for signs of exploitation or process name spoofing attempts
• Implement application whitelisting to restrict execution of executables from non-standard locations
• Enable additional endpoint monitoring to detect renamed executables attempting driver communication
• Consider network segmentation to limit lateral movement if exploitation is suspected

Patch Information

Organizations should monitor the OpenEDR GitHub Repository and OpenEDR Official Website for security updates addressing this vulnerability. The GitHub Issue #49 Discussion provides additional context and tracking for this security issue. For detailed technical analysis of the vulnerability mechanism, refer to the Scavenger Security Blog Post.

Workarounds

• Implement strict application control policies that validate executable signatures before allowing kernel driver communication
• Deploy additional endpoint protection layers that perform robust process identity verification
• Restrict user permissions to minimize the ability to create and execute arbitrary executables
• Monitor for and block execution of processes with trusted EDR names from untrusted directories using Windows Defender Application Control (WDAC) or similar technologies

# Example: Configure AppLocker rule to block execution of csrss.exe from non-system directories
# This PowerShell command creates a deny rule for executables matching trusted names outside System32
New-AppLockerPolicy -RuleType Executable -User Everyone -Action Deny `
  -Path "%USERPROFILE%\*\csrss.exe" -PolicyType Deny