CVE-2025-34396
📋 TL;DR
MailEnable versions before 10.54 have a DLL hijacking vulnerability where the administrative executable loads MEAINFY.DLL from its directory without proper validation. Local attackers with write access can plant a malicious DLL to execute arbitrary code with the process's privileges, potentially leading to privilege escalation. This affects MailEnable installations where administrative tools are used with elevated rights.
💻 Affected Systems
- MailEnable
📦 What is this software?
Mailenable by Mailenable
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to SYSTEM/administrator level if administrative executable runs with elevated privileges, allowing complete system compromise.
Likely Case
Local authenticated users gaining administrative privileges on the MailEnable server, enabling data theft, service disruption, or lateral movement.
If Mitigated
Limited impact if proper file permissions prevent unauthorized writes to MailEnable directories and administrative tools aren't run with elevated rights.
🎯 Exploit Status
Requires local write permissions to MailEnable directories; DLL hijacking techniques are well-documented and easy to implement.
🛠️ 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 official website. 2. Run the installer to upgrade. 3. Restart MailEnable services and affected systems.
🔧 Temporary Workarounds
Restrict directory permissions
windowsSet strict ACLs on MailEnable installation directories to prevent unauthorized writes.
icacls "C:\Program Files\MailEnable" /deny Users:(OI)(CI)W
icacls "C:\Program Files (x86)\MailEnable" /deny Users:(OI)(CI)W
Use secure DLL search order
windowsConfigure system-wide SafeDllSearchMode to prioritize system directories over application directories.
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager" /v SafeDllSearchMode /t REG_DWORD /d 1 /f
🧯 If You Can't Patch
- Apply strict file permissions to MailEnable directories, denying write access to non-administrative users.
- Avoid running MailEnable administrative tools with elevated privileges unless absolutely necessary.
🔍 How to Verify
Check if Vulnerable:
Check MailEnable version in Control Panel > Programs and Features or via 'wmic product where name="MailEnable" get version' command.Check Version:
wmic product where name="MailEnable" get versionVerify Fix Applied:
Confirm version is 10.54 or higher and verify MEAINFY.DLL exists in the installation directory with proper digital signatures.📡 Detection & Monitoring
Log Indicators:
- Failed DLL loading events in Windows Event Logs (Event ID 1000)
- Unexpected process creation from MailEnable executables
Network Indicators:
- None - this is a local attack
SIEM Query:
EventID=1000 AND SourceName="Application Error" AND ProcessName LIKE "%MailEnable%" AND Message LIKE "%MEAINFY.DLL%"