CVE-2025-54353
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in Fortinet FortiSandbox that allows attackers to inject malicious scripts via crafted HTTP requests. The vulnerability affects multiple versions of FortiSandbox across different release branches. Successful exploitation could enable attackers to execute arbitrary JavaScript in the context of authenticated users.
💻 Affected Systems
- Fortinet FortiSandbox
📦 What is this software?
Fortisandbox by Fortinet
Fortisandbox by Fortinet
Fortisandbox by Fortinet
Fortisandbox by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
An attacker could steal administrator session cookies, perform actions as authenticated users, or redirect users to malicious sites, potentially leading to full system compromise if combined with other vulnerabilities.
Likely Case
Attackers could steal session tokens or credentials from authenticated users, potentially gaining unauthorized access to the FortiSandbox management interface.
If Mitigated
With proper input validation and output encoding, the attack would be prevented, and impact would be limited to failed exploitation attempts.
🎯 Exploit Status
Exploitation requires the attacker to craft malicious HTTP requests. The advisory suggests the attack vector is through the web interface, which typically requires some level of access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Upgrade to FortiSandbox 5.0.3 or later, 4.4.8 or later. Versions 4.2 and 4.0 are end-of-life and should be upgraded to supported versions.
Vendor Advisory: https://fortiguard.fortinet.com/psirt/FG-IR-25-477
Restart Required: Yes
Instructions:
1. Download the latest firmware from Fortinet support portal. 2. Backup current configuration. 3. Apply firmware update via web interface or CLI. 4. Reboot the appliance. 5. Verify the update was successful.
🔧 Temporary Workarounds
Web Application Firewall (WAF) Rules
allImplement WAF rules to block XSS payloads targeting FortiSandbox endpoints
Network Segmentation
allRestrict access to FortiSandbox management interface to trusted IP addresses only
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to mitigate XSS impact
- Enable HTTP-only and secure flags on session cookies to limit credential theft
🔍 How to Verify
Check if Vulnerable:
Check FortiSandbox firmware version via web interface (System > Dashboard) or CLI command 'get system status'Check Version:
get system status | grep VersionVerify Fix Applied:
Verify firmware version is 5.0.3 or later, or 4.4.8 or later. Test XSS payloads against the web interface to confirm they are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests containing script tags or JavaScript payloads
- Multiple failed login attempts followed by successful login from different IP
Network Indicators:
- HTTP requests with suspicious parameters containing script tags or JavaScript code
- Traffic to FortiSandbox web interface from unexpected sources
SIEM Query:
source="fortisandbox" AND (http_request CONTAINS "<script>" OR http_request CONTAINS "javascript:" OR http_request CONTAINS "onerror=" OR http_request CONTAINS "onload=")