CVE-2024-26007
📋 TL;DR
An unauthenticated attacker can send crafted HTTP requests to the FortiOS administrative interface, causing a denial of service (DoS) that disrupts management access. This affects Fortinet FortiOS version 7.4.1 systems with exposed administrative interfaces. The vulnerability stems from improper handling of exceptional conditions in the web interface.
💻 Affected Systems
- Fortinet FortiOS
📦 What is this software?
Fortios by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete unavailability of the administrative interface, preventing management access and potentially requiring physical console access or reboot to restore functionality.
Likely Case
Temporary disruption of administrative web interface, requiring service restart or waiting for automatic recovery, while data plane traffic continues unaffected.
If Mitigated
No impact if administrative interface is not exposed to untrusted networks or if proper network segmentation is in place.
🎯 Exploit Status
The vulnerability requires no authentication and can be triggered via HTTP requests to the administrative interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.4.2 or later
Vendor Advisory: https://fortiguard.com/psirt/FG-IR-24-017
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download FortiOS 7.4.2 or later from Fortinet support portal. 3. Upload firmware to FortiGate device. 4. Install firmware update via CLI or web interface. 5. Reboot device after installation completes.
🔧 Temporary Workarounds
Restrict Administrative Interface Access
allLimit access to administrative interface to trusted IP addresses only.
config system interface
edit <interface_name>
set allowaccess https ssh
set trust-ip-1 <trusted_ip>/<mask>
end
Disable HTTP Administrative Access
allDisable HTTP access to administrative interface, require HTTPS only.
config system global
set admin-https-redirect enable
set admin-sport 443
end
🧯 If You Can't Patch
- Implement strict network access controls to limit administrative interface access to trusted management networks only.
- Deploy network-based intrusion prevention systems (IPS) with signatures for FortiOS DoS attacks to detect and block exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check FortiOS version via CLI: 'get system status' and verify if version is 7.4.1.Check Version:
get system status | grep VersionVerify Fix Applied:
After patching, verify version is 7.4.2 or later using 'get system status' command.📡 Detection & Monitoring
Log Indicators:
- Multiple HTTP requests to administrative interface from single source in short timeframe
- Web interface service restart events in logs
- Increased error rates in web interface logs
Network Indicators:
- Unusual HTTP traffic patterns to administrative interface ports (typically 80, 443, or custom admin ports)
- Multiple connection attempts to admin interface from untrusted sources
SIEM Query:
source="fortigate" (eventtype="web-interface" OR eventtype="system") (message="*restart*" OR message="*crash*")