CVE-2025-48483
📋 TL;DR
FreeScout versions before 1.8.180 are vulnerable to stored XSS attacks through mail signature sanitization. Attackers can inject malicious HTML/JavaScript that executes when users view emails, potentially stealing session cookies or sensitive data. Administrators viewing malicious emails could also be vulnerable to CSRF attacks.
💻 Affected Systems
- FreeScout
📦 What is this software?
Freescout by Freescout
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator session cookies, gain full system access, and use CSRF to modify system settings or create backdoor accounts.
Likely Case
Attackers steal user session cookies to access help desk tickets, customer data, and perform unauthorized actions within compromised accounts.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before execution, preventing exploitation.
🎯 Exploit Status
Exploitation requires authenticated access to create/modify mail signatures. The vulnerability is in the mail signature sanitization process.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.8.180
Vendor Advisory: https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-g2vq-qwx2-pc2m
Restart Required: No
Instructions:
1. Backup your FreeScout installation and database. 2. Download version 1.8.180 from the official repository. 3. Replace existing files with new version. 4. Run any database migrations if required. 5. Clear application cache.
🔧 Temporary Workarounds
Disable HTML mail signatures
allConfigure FreeScout to use plain text signatures only to prevent HTML injection
Implement WAF rules
allAdd web application firewall rules to block suspicious HTML/JavaScript in POST requests
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution
- Restrict user permissions for mail signature modification to trusted administrators only
🔍 How to Verify
Check if Vulnerable:
Check FreeScout version in admin panel or via 'php artisan --version' command. If version is below 1.8.180, system is vulnerable.Check Version:
php artisan --versionVerify Fix Applied:
After updating, verify version shows 1.8.180 or higher. Test mail signature functionality with HTML input to ensure proper sanitization.📡 Detection & Monitoring
Log Indicators:
- Unusual HTML/JavaScript patterns in mail signature updates
- Multiple failed signature update attempts with script tags
Network Indicators:
- POST requests to signature endpoints containing script tags or event handlers
SIEM Query:
source="freescout.log" AND ("signature" AND ("script" OR "javascript" OR "onclick"))