CVE-2025-34400
📋 TL;DR
MailEnable versions before 10.54 contain a reflected XSS vulnerability in the AddressesTo parameter of the address book page. Attackers can craft malicious URLs that execute JavaScript in victims' browsers when they attempt to send emails, potentially stealing session cookies or performing actions as the authenticated user. This affects all MailEnable installations using vulnerable versions.
💻 Affected Systems
- MailEnable
📦 What is this software?
Mailenable by Mailenable
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal authenticated session cookies, hijack user accounts, redirect to phishing sites, and perform actions as the victim including sending emails, accessing contacts, and modifying settings.
Likely Case
Attackers steal non-HttpOnly session cookies to hijack authenticated sessions, redirect users to malicious sites, or inject phishing forms into the email interface.
If Mitigated
With HttpOnly cookies and proper session management, impact reduces to UI manipulation, phishing attempts, and limited session hijacking.
🎯 Exploit Status
Exploitation requires social engineering to get victim to click malicious link. No authentication needed to trigger vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.54
Vendor Advisory: https://mailenable.com/Standard-ReleaseNotes.txt
Restart Required: Yes
Instructions:
1. Download MailEnable version 10.54 or later from vendor website. 2. Backup current installation. 3. Run installer to upgrade. 4. Restart MailEnable services. 5. Verify version shows 10.54 or higher.
🔧 Temporary Workarounds
Input Validation Filter
allImplement web application firewall or input validation to sanitize AddressesTo parameter
Disable Webmail Access
windowsTemporarily disable webmail interface if not required
Stop MailEnable web services or block port 8080/8443
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution
- Configure web application firewall to block XSS payloads in AddressesTo parameter
🔍 How to Verify
Check if Vulnerable:
Test by accessing /Mondo/lang/sys/Forms/AddressBook.aspx?AddressesTo=<script>alert('XSS')</script> and checking if script executesCheck Version:
Check MailEnable version in administrative console or via registry: HKEY_LOCAL_MACHINE\SOFTWARE\MailEnableVerify Fix Applied:
After patching, test same payload - should be sanitized and not execute📡 Detection & Monitoring
Log Indicators:
- HTTP GET requests to AddressBook.aspx with script tags or JavaScript in AddressesTo parameter
- Unusual length or encoding in AddressesTo parameter
Network Indicators:
- HTTP requests containing <script> or JavaScript functions in URL parameters
- Multiple failed XSS attempts from same source
SIEM Query:
source="mailenable.log" AND uri="*AddressBook.aspx*" AND (param="*<script>*" OR param="*javascript:*" OR param="*onerror=*" OR param="*onload=*")