CVE-2023-25602
📋 TL;DR
This CVE describes a stack-based buffer overflow vulnerability in Fortinet FortiWeb web application firewalls. Attackers can exploit it by sending specially crafted command arguments to execute arbitrary code or commands on affected devices. All FortiWeb versions from 5.6 through 6.4 are affected.
💻 Affected Systems
- Fortinet FortiWeb
📦 What is this software?
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
Fortiweb by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code with the privileges of the vulnerable process, potentially leading to full device takeover, data exfiltration, or lateral movement into protected networks.
Likely Case
Remote code execution allowing attackers to modify configurations, disable security controls, install backdoors, or use the device as a pivot point into internal networks.
If Mitigated
Limited impact if proper network segmentation and access controls prevent exploitation attempts from reaching vulnerable interfaces.
🎯 Exploit Status
The vulnerability requires specially crafted command arguments but does not require authentication. Exploitation complexity is medium due to the need for buffer overflow exploitation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FortiWeb 6.4.3, 6.3.18, 6.2.7, 6.1.3, 6.0.8, 5.9.2
Vendor Advisory: https://fortiguard.com/psirt/FG-IR-21-234
Restart Required: Yes
Instructions:
1. Download the appropriate firmware update from the Fortinet support portal. 2. Backup current configuration. 3. Upload and install the firmware update via the web interface or CLI. 4. Reboot the device after installation completes. 5. Verify the new firmware version is running.
🔧 Temporary Workarounds
Restrict Management Access
allLimit access to FortiWeb management interfaces to trusted IP addresses only
config system interface
edit <interface_name>
set allowaccess https ssh ping
set trust-ip-1 <trusted_ip>/<mask>
end
Enable Intrusion Prevention
allConfigure FortiWeb's built-in IPS to detect and block buffer overflow attempts
config waf ips
set status enable
set signature-set-threshold high
end
🧯 If You Can't Patch
- Implement strict network segmentation to isolate FortiWeb devices from untrusted networks
- Deploy additional network-based intrusion detection/prevention systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check the FortiWeb firmware version via the web interface (System > Dashboard) or CLI command 'get system status'Check Version:
get system status | grep VersionVerify Fix Applied:
Verify the firmware version is at or above the patched versions: 6.4.3, 6.3.18, 6.2.7, 6.1.3, 6.0.8, or 5.9.2📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns in FortiWeb logs
- Multiple failed command attempts with malformed arguments
- Process crashes or restarts in system logs
Network Indicators:
- Unusual traffic patterns to FortiWeb management interfaces
- Multiple connection attempts with malformed command arguments
SIEM Query:
source="fortiweb" AND (event_type="command_execution" OR event_type="system_crash") AND args="*overflow*" OR args="*buffer*"