CVE-2021-38416
📋 TL;DR
Delta Electronics DIALink versions 1.2.4.0 and earlier have a DLL hijacking vulnerability due to insecure library loading. This allows attackers to execute arbitrary code with the privileges of the DIALink software, potentially compromising the entire system where it's installed. Industrial control systems using this software for device management are affected.
💻 Affected Systems
- Delta Electronics DIALink
📦 What is this software?
Dialink by Deltaww
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining administrative privileges, allowing installation of persistent malware, data theft, and disruption of industrial operations.
Likely Case
Local privilege escalation leading to system takeover, enabling lateral movement within industrial networks and potential manipulation of connected devices.
If Mitigated
Limited impact if software runs with minimal privileges and proper application whitelisting is enforced, though DLL hijacking could still occur.
🎯 Exploit Status
Requires local access or ability to place malicious DLL in application directory. DLL hijacking is a well-known attack vector with established techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.2.5.0 or later
Vendor Advisory: https://www.deltaww.com/en-US/Support/Downloads/Detail?code=DIALink
Restart Required: Yes
Instructions:
1. Download DIALink version 1.2.5.0 or later from Delta Electronics website. 2. Uninstall previous version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Application Hardening
windowsRun DIALink with minimal privileges and implement application whitelisting
Directory Permissions
windowsRestrict write permissions to DIALink installation directory and Windows system directories
icacls "C:\Program Files\Delta Electronics\DIALink" /deny Everyone:(OI)(CI)W
🧯 If You Can't Patch
- Isolate DIALink systems on separate network segments with strict access controls
- Implement application control solutions to prevent unauthorized DLL loading
🔍 How to Verify
Check if Vulnerable:
Check DIALink version in Help > About menu. If version is 1.2.4.0 or earlier, system is vulnerable.Check Version:
Not applicable - check via application GUIVerify Fix Applied:
Verify DIALink version is 1.2.5.0 or later in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing DLL loading from unusual locations
- Process creation events for DIALink with suspicious parent processes
Network Indicators:
- Unexpected outbound connections from DIALink process
- Network traffic to unknown external IPs
SIEM Query:
source="Windows Security" EventCode=4688 ProcessName="DIALink.exe" | search DLLPath!="*\Windows\*" DLLPath!="*\Program Files\Delta Electronics\*"