CVE-2023-26290
📋 TL;DR
This is a reflected cross-site scripting (XSS) vulnerability in Forcepoint Cloud Security Gateway and Web Security products. It allows attackers to inject malicious scripts into the login_reset_request.mhtml modules, which could lead to session hijacking or credential theft. Affected systems include Forcepoint Cloud Security Gateway Portal, Email Security Cloud, and Web Security Portal on Hybrid deployments.
💻 Affected Systems
- Forcepoint Cloud Security Gateway (CSG) Portal
- Forcepoint Email Security Cloud
- Forcepoint Web Security Portal on Hybrid
📦 What is this software?
Web Security by Forcepoint
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, hijack user sessions, redirect users to malicious sites, or perform actions on behalf of authenticated users.
Likely Case
Attackers craft phishing emails with malicious links that execute scripts in the victim's browser when they visit the vulnerable reset request page.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before execution.
🎯 Exploit Status
Reflected XSS vulnerabilities are commonly exploited via phishing campaigns. No authentication required to trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions updated on or after March 29, 2023
Vendor Advisory: https://support.forcepoint.com/s/article/000041617
Restart Required: Yes
Instructions:
1. Log into Forcepoint support portal
2. Download the latest version for your product
3. Apply the update according to Forcepoint documentation
4. Restart affected services
5. Verify the fix is applied
🔧 Temporary Workarounds
Input Validation Web Application Firewall Rule
allConfigure WAF to block requests containing suspicious script patterns to the login_reset_request.mhtml endpoint
WAF-specific configuration - consult your WAF documentation
Temporary URL Restriction
allRestrict access to the vulnerable endpoint using network controls
firewall rules to limit access to /login_reset_request.mhtml
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution
- Deploy web application firewall with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Test the login_reset_request.mhtml endpoint with XSS payloads like <script>alert('test')</script> in URL parametersCheck Version:
Check product version in admin interface or via Forcepoint management consoleVerify Fix Applied:
After patching, test the same endpoint with XSS payloads - scripts should be properly encoded or blocked📡 Detection & Monitoring
Log Indicators:
- Unusual requests to login_reset_request.mhtml with script tags or JavaScript code
- Multiple failed login attempts from same IP
- Requests with encoded script payloads in parameters
Network Indicators:
- HTTP requests containing <script> tags or JavaScript functions in URL parameters
- Traffic to login_reset_request.mhtml with suspicious parameter values
SIEM Query:
source="web_logs" AND uri="*login_reset_request.mhtml*" AND (param="*<script>*" OR param="*javascript:*" OR param="*onload=*" OR param="*onerror=*")