CVE-2025-34403
📋 TL;DR
MailEnable versions before 10.54 contain a reflected XSS vulnerability in the AddressBook.aspx page's FieldTo parameter. 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 users running 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 within the MailEnable application.
Likely Case
Attackers steal non-HttpOnly session cookies to hijack authenticated sessions, potentially accessing email accounts and sensitive communications.
If Mitigated
With proper input validation and output encoding, the attack fails to execute malicious JavaScript, limiting impact to parameter reflection without code execution.
🎯 Exploit Status
Exploitation requires victim interaction (clicking malicious link) but uses standard XSS techniques with low technical complexity.
🛠️ 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 the official website. 2. Run the installer to upgrade your existing installation. 3. Restart MailEnable services and IIS if applicable.
🔧 Temporary Workarounds
Input Validation Filter
windowsImplement web application firewall (WAF) rules or IIS URL rewrite rules to block malicious FieldTo parameter values containing script tags or JavaScript syntax.
Disable Web Interface
windowsTemporarily disable the MailEnable web interface if not required, using only desktop email clients.
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent inline script execution
- Deploy web application firewall with XSS protection rules for the /Mondo/lang/sys/Forms/AddressBook.aspx endpoint
🔍 How to Verify
Check if Vulnerable:
Access /Mondo/lang/sys/Forms/AddressBook.aspx?FieldTo=testXSS and check if the parameter value is reflected unsanitized in the JavaScript variable var fieldTo.Check Version:
Check MailEnable version in the administration console or via the installed program details in Windows.Verify Fix Applied:
After patching, test with the same payload - the FieldTo parameter should be properly encoded or sanitized in the output.📡 Detection & Monitoring
Log Indicators:
- HTTP GET requests to /Mondo/lang/sys/Forms/AddressBook.aspx with FieldTo parameter containing script tags or JavaScript code
- Unusual parameter lengths or special characters in FieldTo values
Network Indicators:
- HTTP requests with malicious JavaScript in FieldTo parameter
- Referer headers containing crafted XSS payloads
SIEM Query:
source="web_logs" AND uri_path="/Mondo/lang/sys/Forms/AddressBook.aspx" AND query_string="*FieldTo=*script*"