CVE-2021-43065
📋 TL;DR
This vulnerability in Fortinet FortiNAC allows attackers to gain elevated privileges by accessing sensitive system data due to incorrect permission assignments. It affects FortiNAC versions 9.2.0, 9.1.3 and below, and 8.8.9 and below. Attackers can exploit this to compromise network access control systems.
💻 Affected Systems
- Fortinet FortiNAC
📦 What is this software?
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to gain administrative control over FortiNAC, modify network access policies, and potentially pivot to other network systems.
Likely Case
Attacker gains elevated privileges to access sensitive network configuration data, modify device access policies, and potentially disrupt network operations.
If Mitigated
Limited impact with proper network segmentation and access controls preventing lateral movement from compromised FortiNAC system.
🎯 Exploit Status
Exploitation requires some level of access to the system. Public proof-of-concept exists in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FortiNAC 9.2.1, 9.1.4, 8.8.10
Vendor Advisory: https://fortiguard.com/advisory/FG-IR-21-178
Restart Required: Yes
Instructions:
1. Download the appropriate patch version from Fortinet support portal. 2. Backup current configuration. 3. Apply the patch following Fortinet's upgrade procedures. 4. Restart the FortiNAC system. 5. Verify the patch was successfully applied.
🔧 Temporary Workarounds
Restrict Access Controls
allImplement strict access controls to limit who can access the FortiNAC management interface.
Network Segmentation
allIsolate FortiNAC systems from other critical network segments to limit potential lateral movement.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate FortiNAC from other critical systems
- Enforce multi-factor authentication and least privilege access for all FortiNAC administrative accounts
🔍 How to Verify
Check if Vulnerable:
Check FortiNAC version via web interface or CLI. If version is 9.2.0, 9.1.3 or below, or 8.8.9 or below, system is vulnerable.Check Version:
ssh admin@fortinac_ip show versionVerify Fix Applied:
Verify FortiNAC version is 9.2.1, 9.1.4, 8.8.10 or higher after patching.📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation attempts
- Multiple failed authentication attempts followed by successful administrative access
- Configuration changes from non-admin accounts
Network Indicators:
- Unusual administrative access patterns to FortiNAC management interface
- Network policy changes from unexpected sources
SIEM Query:
source="fortinac" AND (event_type="privilege_escalation" OR user_change="admin" OR config_modify)