CVE-2022-26019
📋 TL;DR
This vulnerability allows authenticated remote attackers with NTP GPS configuration privileges to overwrite files on pfSense systems, potentially leading to remote code execution. It affects pfSense CE versions before 2.6.0 and pfSense Plus versions before 22.01. Attackers need existing administrative access to the web interface to exploit this flaw.
💻 Affected Systems
- pfSense CE
- pfSense Plus
📦 What is this software?
Pfsense by Netgate
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root-level arbitrary command execution, allowing complete control of the firewall/router, data exfiltration, and lateral movement into connected networks.
Likely Case
Privilege escalation from limited administrative access to full system control, configuration manipulation, and persistence establishment on the firewall device.
If Mitigated
Limited to NTP GPS configuration changes only, with no file system access or command execution capabilities.
🎯 Exploit Status
Exploitation requires authenticated access to the web interface with specific privileges. The vulnerability involves improper path validation in NTP GPS configuration functionality.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: pfSense CE 2.6.0, pfSense Plus 22.01
Vendor Advisory: https://docs.netgate.com/downloads/pfSense-SA-22_01.webgui.asc
Restart Required: No
Instructions:
1. Log into pfSense web interface. 2. Navigate to System > Update. 3. Select 'Update' tab. 4. Click 'Confirm' to update to latest version. 5. Apply changes when prompted.
🔧 Temporary Workarounds
Restrict NTP GPS Configuration Access
allRemove NTP GPS configuration privileges from administrative users who don't require them.
Network Segmentation
allRestrict access to pfSense web interface to trusted management networks only.
🧯 If You Can't Patch
- Implement strict access controls to limit which administrators can modify NTP GPS settings
- Monitor for unusual file system modifications and NTP configuration changes
🔍 How to Verify
Check if Vulnerable:
Check pfSense version via web interface Dashboard or CLI: pfSense-versionCheck Version:
pfSense-versionVerify Fix Applied:
Verify version is pfSense CE >= 2.6.0 or pfSense Plus >= 22.01📡 Detection & Monitoring
Log Indicators:
- Unauthorized NTP GPS configuration changes
- Unexpected file modifications in system directories
- Web interface authentication from unusual sources
Network Indicators:
- Unusual outbound connections from pfSense device
- Unexpected configuration changes to NTP services
SIEM Query:
source="pfSense" AND (event_type="config_change" AND config_item="ntp" OR event_type="file_modification" AND file_path CONTAINS "/etc/")