CVE-2021-43077
📋 TL;DR
This SQL injection vulnerability in Fortinet FortiWLM allows attackers to execute arbitrary SQL commands via crafted HTTP requests to AP monitor handlers. Successful exploitation could lead to unauthorized code execution, data theft, or complete system compromise. Affected organizations include those running vulnerable FortiWLM versions 8.6.2 and below, 8.5.2 and below, 8.4.2 and below, and 8.3.2 and below.
💻 Affected Systems
- Fortinet FortiWLM
📦 What is this software?
Fortiwlm by Fortinet
Fortiwlm by Fortinet
Fortiwlm by Fortinet
Fortiwlm by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with administrative access, data exfiltration, lateral movement to other systems, and persistent backdoor installation.
Likely Case
Unauthorized database access leading to sensitive information disclosure, configuration modification, or denial of service.
If Mitigated
Limited impact due to network segmentation, proper input validation, and restricted database permissions.
🎯 Exploit Status
The advisory indicates exploitation via crafted HTTP requests, suggesting relatively straightforward exploitation for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions 8.6.3, 8.5.3, 8.4.3, 8.3.3 and above
Vendor Advisory: https://fortiguard.com/advisory/FG-IR-21-189
Restart Required: Yes
Instructions:
1. Download the appropriate patched version from Fortinet support portal. 2. Backup current configuration. 3. Install the update following Fortinet's upgrade procedures. 4. Restart the FortiWLM system. 5. Verify the update was successful.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to FortiWLM management interfaces to trusted IP addresses only.
Configure firewall rules to allow only authorized IPs to access FortiWLM HTTP/HTTPS ports
Web Application Firewall
allDeploy a WAF with SQL injection protection rules in front of FortiWLM.
Configure WAF to inspect and block SQL injection patterns targeting /api/monitor/ap/* endpoints
🧯 If You Can't Patch
- Implement strict network segmentation to isolate FortiWLM from untrusted networks
- Enable detailed logging and monitoring for suspicious HTTP requests to AP monitor handlers
🔍 How to Verify
Check if Vulnerable:
Check FortiWLM version via web interface or CLI. If version is 8.6.2 or below, 8.5.2 or below, 8.4.2 or below, or 8.3.2 or below, the system is vulnerable.Check Version:
From FortiWLM CLI: get system status | grep VersionVerify Fix Applied:
Verify the installed version is 8.6.3+, 8.5.3+, 8.4.3+, or 8.3.3+ and test that SQL injection attempts are properly blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL errors in application logs
- Multiple failed login attempts followed by successful access
- HTTP requests with SQL syntax in parameters to /api/monitor/ap/* endpoints
Network Indicators:
- Unusual database connection patterns from FortiWLM
- HTTP requests containing SQL keywords (SELECT, UNION, INSERT, etc.) to FortiWLM
SIEM Query:
source="fortiwlm" AND (url="*api/monitor/ap*" AND (param="*SELECT*" OR param="*UNION*" OR param="*INSERT*" OR param="*DELETE*"))