CVE-2021-24007
📋 TL;DR
This CVE describes SQL injection vulnerabilities in FortiMail email security appliances that allow unauthenticated attackers to execute arbitrary SQL commands via crafted HTTP requests. Attackers could potentially execute unauthorized code or commands on affected systems. Organizations running FortiMail versions before 6.4.4 are affected.
💻 Affected Systems
- FortiMail
📦 What is this software?
Fortimail by Fortinet
Fortimail by Fortinet
Fortimail by Fortinet
Fortimail by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, steal sensitive data, pivot to internal networks, and maintain persistent access.
Likely Case
Data exfiltration, email system compromise, credential theft, and potential lateral movement within the network.
If Mitigated
Limited impact with proper network segmentation, WAF protection, and restricted database permissions.
🎯 Exploit Status
SQL injection vulnerabilities are well-understood and often weaponized quickly. The unauthenticated nature makes exploitation straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.4.4 and later
Vendor Advisory: https://fortiguard.com/advisory/FG-IR-21-012
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download FortiMail 6.4.4 or later from Fortinet support portal. 3. Upload firmware to FortiMail via web interface. 4. Install update. 5. Reboot system. 6. Verify version and functionality.
🔧 Temporary Workarounds
Web Application Firewall Rules
allImplement WAF rules to block SQL injection patterns targeting FortiMail endpoints
# Example WAF rule for SQL injection detection
# Configure in your WAF solution to block patterns like: UNION SELECT, ' OR '1'='1, ;--
Network Segmentation
linuxRestrict access to FortiMail management interfaces to trusted IP addresses only
# Example firewall rule
# iptables -A INPUT -p tcp --dport 443 -s trusted_network -j ACCEPT
# iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit FortiMail exposure to only necessary IP addresses
- Deploy a web application firewall (WAF) in front of FortiMail with SQL injection detection rules
🔍 How to Verify
Check if Vulnerable:
Check FortiMail version via web interface: System > Dashboard > System Information. If version is below 6.4.4, system is vulnerable.Check Version:
# From FortiMail CLI:
get system status
# Look for 'Version: FortiMail-6.4.4' or higherVerify Fix Applied:
After patching, verify version is 6.4.4 or higher in System > Dashboard > System Information. Test email functionality to ensure patch didn't break services.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages in logs
- Multiple failed login attempts followed by successful access
- Unexpected database queries in application logs
Network Indicators:
- HTTP requests containing SQL keywords (SELECT, UNION, INSERT, etc.) to FortiMail endpoints
- Unusual outbound connections from FortiMail to external systems
SIEM Query:
source="fortimail" AND ("sql" OR "union" OR "select" OR "' OR '1'='1") AND response_code=200