CVE-2023-23777
📋 TL;DR
This vulnerability allows privileged attackers to execute arbitrary bash commands on FortiWeb web application firewalls through crafted CLI backup parameters. It affects FortiWeb versions 7.0.1 and below, 6.4 all versions, and 6.3.18 and below. Attackers with administrative access can exploit this to gain full system control.
💻 Affected Systems
- FortiWeb Web Application Firewall
📦 What is this software?
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to install persistent backdoors, exfiltrate sensitive data, pivot to internal networks, and disrupt operations.
Likely Case
Privileged attacker gains root shell access to execute arbitrary commands, potentially installing malware or modifying configurations.
If Mitigated
Limited impact with proper network segmentation, privileged access controls, and monitoring in place.
🎯 Exploit Status
Requires authenticated privileged access. Exploitation involves crafting malicious backup parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.0.2, 6.3.19, 6.4.1
Vendor Advisory: https://fortiguard.com/psirt/FG-IR-22-131
Restart Required: Yes
Instructions:
1. Download appropriate firmware version from Fortinet support portal. 2. Backup current configuration. 3. Upload and install firmware via web GUI or CLI. 4. Reboot device. 5. Verify version after reboot.
🔧 Temporary Workarounds
Restrict CLI Access
allLimit CLI access to trusted administrative accounts only and implement strong authentication.
Network Segmentation
allIsolate FortiWeb management interfaces from untrusted networks.
🧯 If You Can't Patch
- Implement strict access controls to limit who can access FortiWeb CLI interface.
- Monitor CLI backup commands and look for unusual parameters or command execution patterns.
🔍 How to Verify
Check if Vulnerable:
Check FortiWeb version via CLI: 'get system status' or web GUI: System > Dashboard. Compare against affected versions.Check Version:
get system status | grep VersionVerify Fix Applied:
After patching, verify version is 7.0.2+, 6.3.19+, or 6.4.1+ using same commands.📡 Detection & Monitoring
Log Indicators:
- Unusual CLI backup commands with suspicious parameters
- Unexpected command execution in system logs
- Multiple failed authentication attempts followed by backup commands
Network Indicators:
- Unusual traffic patterns from FortiWeb management interface
- Unexpected outbound connections from FortiWeb
SIEM Query:
source="fortiweb" AND (event_type="cli_command" AND command="backup" AND parameters CONTAINS "|" OR ";" OR "$")