CVE-2025-34422
📋 TL;DR
MailEnable versions before 10.54 have a DLL hijacking vulnerability where the administrative executable loads MEAIPC.DLL from its installation directory without proper security checks. Local attackers with write access to that directory can plant malicious DLLs to execute arbitrary code with the process's privileges. This affects MailEnable installations where local users have write permissions to the installation directory.
💻 Affected Systems
- MailEnable
📦 What is this software?
Mailenable by Mailenable
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to SYSTEM/administrator level if the vulnerable process runs with elevated privileges, leading to complete system compromise.
Likely Case
Local authenticated users gain code execution with the privileges of the MailEnable administrative process, potentially allowing lateral movement or persistence.
If Mitigated
Limited impact if proper file system permissions restrict write access to the installation directory to trusted administrators only.
🎯 Exploit Status
Exploitation requires creating a malicious DLL with specific exports and placing it in the installation directory. No authentication bypass needed beyond local file system access.
🛠️ 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. 3. Restart the MailEnable services and any administrative processes.
🔧 Temporary Workarounds
Restrict installation directory permissions
windowsRemove write permissions for non-administrative users from the MailEnable installation directory to prevent DLL planting.
icacls "C:\Program Files\MailEnable" /deny Users:(OI)(CI)W
icacls "C:\Program Files (x86)\MailEnable" /deny Users:(OI)(CI)W
Enable Safe DLL Search Mode
windowsConfigure Windows to search system directories before current directory when loading DLLs.
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager" /v SafeDllSearchMode /t REG_DWORD /d 1 /f
🧯 If You Can't Patch
- Restrict local user access to MailEnable installation directories using strict file system permissions.
- Monitor for unauthorized DLL files in MailEnable directories using file integrity monitoring tools.
🔍 How to Verify
Check if Vulnerable:
Check MailEnable version in administrative interface or via installed programs list. Versions below 10.54 are vulnerable.Check Version:
Check Help > About in MailEnable administrative console or examine installed programs in Windows Control Panel.Verify Fix Applied:
Verify MailEnable version is 10.54 or higher and check that MEAIPC.DLL loading uses secure search paths.📡 Detection & Monitoring
Log Indicators:
- Unexpected DLL loading events from MailEnable processes in Windows Event Logs (Event ID 7)
- Creation of MEAIPC.DLL files in MailEnable directories by non-administrative users
Network Indicators:
- No direct network indicators as this is a local attack
SIEM Query:
EventID=7 AND ProcessName LIKE '%mailenable%' AND ImageLoaded LIKE '%MEAIPC.DLL%' AND NOT UserName IN ('SYSTEM', 'Administrator')