CVE-2025-34402
📋 TL;DR
MailEnable versions before 10.54 contain a reflected cross-site scripting vulnerability in the FieldCc parameter of the AddressBook.aspx 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 users running vulnerable versions.
💻 Affected Systems
- MailEnable
📦 What is this software?
Mailenable by Mailenable
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal session cookies, hijack authenticated sessions, redirect users to malicious sites, and perform actions as the victim including sending emails, accessing contacts, or modifying account settings.
Likely Case
Attackers steal non-HttpOnly session cookies to hijack authenticated sessions, potentially accessing email accounts and sensitive information.
If Mitigated
With proper input validation and output encoding, the vulnerability is prevented; with HttpOnly cookies, cookie theft is mitigated but other XSS impacts remain.
🎯 Exploit Status
Exploitation requires user interaction (clicking malicious link) but is straightforward once the payload is crafted.
🛠️ 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 vendor website. 2. Backup current configuration and data. 3. Run the installer to upgrade. 4. Restart MailEnable services.
🔧 Temporary Workarounds
Input Validation Filter
allImplement web application firewall (WAF) rules or input validation to sanitize FieldCc parameter values.
WAF rule: Block requests containing script tags or JavaScript in FieldCc parameter
Disable Webmail Access
windowsTemporarily disable webmail interface if not required, forcing users to use desktop email clients.
IIS: Disable /Mondo/ virtual directory
Windows Firewall: Block port 80/443 to webmail
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution from untrusted sources.
- Set all cookies as HttpOnly and Secure to mitigate session cookie theft.
🔍 How to Verify
Check if Vulnerable:
Access /Mondo/lang/sys/Forms/AddressBook.aspx?FieldCc=test'><script>alert('XSS')</script> and check if script executes in browser.Check Version:
Check MailEnable version in Control Panel or via registry: HKEY_LOCAL_MACHINE\SOFTWARE\MailEnableVerify Fix Applied:
After patching, test with same payload; script should not execute and input should be properly encoded.📡 Detection & Monitoring
Log Indicators:
- HTTP GET requests to AddressBook.aspx with suspicious FieldCc parameter values containing script tags or JavaScript
Network Indicators:
- Unusual outbound connections from webmail server following XSS payload delivery
SIEM Query:
source="webmail_logs" AND uri="/Mondo/lang/sys/Forms/AddressBook.aspx" AND query="*FieldCc=*script*"