CVE-2023-22633
📋 TL;DR
This vulnerability allows unauthenticated attackers to perform denial-of-service (DoS) attacks on FortiNAC devices by exploiting improper access controls in client-secure renegotiation. It affects FortiNAC-F 7.2.0 and multiple FortiNAC versions up to 9.4.1. Organizations using these vulnerable network access control systems are at risk.
💻 Affected Systems
- FortiNAC-F
- FortiNAC
📦 What is this software?
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac by Fortinet
Fortinac F by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of FortiNAC device, preventing network access control and potentially affecting network availability for managed devices.
Likely Case
Temporary DoS causing service interruption until device restart or attack cessation.
If Mitigated
Minimal impact with proper network segmentation and DoS protection in place.
🎯 Exploit Status
Unauthenticated DoS attacks are relatively simple to execute once the vulnerability details are understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FortiNAC 9.4.2, 9.2.7, 9.1.9, and later versions
Vendor Advisory: https://fortiguard.com/psirt/FG-IR-22-521
Restart Required: Yes
Instructions:
1. Download the patched version from Fortinet support portal. 2. Backup current configuration. 3. Apply the update following Fortinet's upgrade procedures. 4. Restart the device to complete installation.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to FortiNAC management interfaces to trusted networks only.
Rate Limiting
allImplement network-level rate limiting on connections to FortiNAC devices.
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach FortiNAC management interfaces
- Deploy DoS protection appliances in front of FortiNAC devices
🔍 How to Verify
Check if Vulnerable:
Check FortiNAC version via web interface: System > Dashboard > System InformationCheck Version:
No CLI command available; use web interface as aboveVerify Fix Applied:
Verify version is 9.4.2 or higher, or 9.2.7/9.1.9 for respective branches📡 Detection & Monitoring
Log Indicators:
- Unusual connection spikes
- Failed renegotiation attempts
- Service restart events
Network Indicators:
- High volume of SSL/TLS renegotiation requests to FortiNAC ports
- Abnormal traffic patterns from single sources
SIEM Query:
source="fortinac" AND (event_type="connection_failure" OR event_type="service_restart")