CVE-2023-37933
📋 TL;DR
This is a stored cross-site scripting (XSS) vulnerability in FortiADC's web management interface. Authenticated attackers can inject malicious scripts via HTTP/HTTPS requests that execute when administrators view affected pages. Affects FortiADC versions 7.4.0, 7.2.0-7.2.1, and all versions before 7.1.3.
💻 Affected Systems
- FortiADC
📦 What is this software?
Fortiadc by Fortinet
Fortiadc by Fortinet
Fortiadc by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could steal administrator session cookies, perform actions as administrators, install backdoors, or pivot to internal networks.
Likely Case
Attackers with valid credentials could steal session tokens to gain administrative access, modify configurations, or deploy malware.
If Mitigated
With proper network segmentation and least privilege access, impact is limited to the FortiADC management interface.
🎯 Exploit Status
Requires authenticated access and knowledge of vulnerable endpoints. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Upgrade to FortiADC 7.4.1, 7.2.2, or 7.1.3 and above
Vendor Advisory: https://fortiguard.com/psirt/FG-IR-23-216
Restart Required: No
Instructions:
1. Download appropriate firmware from Fortinet support portal. 2. Backup configuration. 3. Upload firmware via GUI or CLI. 4. Apply update. 5. Verify version after update.
🔧 Temporary Workarounds
Restrict Management Access
allLimit access to FortiADC management interface to trusted IP addresses only
config system interface
edit <mgmt_interface>
set allowaccess https
set trust-ip-1 <trusted_ip>
end
Enable Content Security Policy
allImplement CSP headers to mitigate XSS impact if supported
🧯 If You Can't Patch
- Implement strict network segmentation to isolate FortiADC management interface
- Enforce strong authentication and session management, including MFA if available
🔍 How to Verify
Check if Vulnerable:
Check FortiADC version via GUI (System > Dashboard) or CLI command: get system statusCheck Version:
get system status | grep VersionVerify Fix Applied:
After patching, verify version is 7.4.1, 7.2.2, 7.1.3 or higher using: get system status📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to management interface
- Multiple failed login attempts followed by successful login
- Administrative actions from unusual user agents or IPs
Network Indicators:
- Suspicious JavaScript payloads in HTTP requests to FortiADC management interface
- Unexpected outbound connections from FortiADC management IP
SIEM Query:
source="fortiadc" AND (http_method="POST" AND uri="/*" AND (content="<script>" OR content="javascript:"))