CVE-2022-27089
📋 TL;DR
This vulnerability allows a local attacker to escalate privileges to SYSTEM level by exploiting an unquoted service path in Fujitsu PlugFree Network's PFNService.exe. It affects users running Fujitsu PlugFree Network version 7.3.0.3 or earlier. Attackers need local access to the system to exploit this vulnerability.
💻 Affected Systems
- Fujitsu PlugFree Network
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full SYSTEM privilege escalation leading to complete system compromise, data theft, persistence establishment, and lateral movement capabilities.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install malware, or access restricted resources on the compromised system.
If Mitigated
Limited impact due to proper access controls, monitoring, and restricted local user privileges preventing successful exploitation.
🎯 Exploit Status
Unquoted service path vulnerabilities are well-understood and relatively easy to exploit with local access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: > 7.3.0.3
Vendor Advisory: https://www.fujitsu.com/global/support/products/software/security/products-fujitsu.html
Restart Required: Yes
Instructions:
1. Download latest version from Fujitsu support portal. 2. Uninstall current version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Modify Service Path Permissions
windowsRestrict write permissions to directories in the service path to prevent malicious executable placement.
icacls "C:\Program Files\Fujitsu\PlugFree Network" /deny Users:(OI)(CI)W
Quote Service Path
windowsManually edit the service configuration to use quoted paths in the service executable path.
sc config PFNService binPath= "\"C:\Program Files\Fujitsu\PlugFree Network\PFNService.exe\""
🧯 If You Can't Patch
- Implement strict least privilege principles for local user accounts
- Monitor for suspicious service modifications and file creation in service path directories
🔍 How to Verify
Check if Vulnerable:
Check service configuration: sc qc PFNService and look for unquoted path containing spaces. Also check installed version in Control Panel > Programs.Check Version:
Check Programs and Features or registry: HKEY_LOCAL_MACHINE\SOFTWARE\Fujitsu\PlugFree NetworkVerify Fix Applied:
Verify service path is quoted: sc qc PFNService should show quoted path. Check installed version is > 7.3.0.3.📡 Detection & Monitoring
Log Indicators:
- Windows Event ID 7045: Service installation/modification
- Unexpected file creation in service path directories
- Process creation from unusual locations
Network Indicators:
- Unusual outbound connections from SYSTEM context processes
SIEM Query:
EventID=7045 AND ServiceName="PFNService" OR ProcessCreation WHERE ImagePath contains "PlugFree Network" AND ParentImage not in approved list