CVE-2017-9638
📋 TL;DR
CVE-2017-9638 is a critical stack-based buffer overflow vulnerability in Mitsubishi E-Designer version 7.52 Build 344 that allows attackers to execute arbitrary code, compromise data integrity, cause denial of service, or crash systems. This affects industrial control system (ICS) environments using this specific version of Mitsubishi's engineering software for programming PLCs. The vulnerability is particularly dangerous because it can be exploited without authentication.
💻 Affected Systems
- Mitsubishi E-Designer
📦 What is this software?
E Designer by Mitsubishielectric
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code on affected systems, potentially leading to manipulation of industrial processes, data theft, or physical damage in industrial environments.
Likely Case
System crashes and denial of service affecting industrial control operations, potentially disrupting manufacturing or critical infrastructure processes.
If Mitigated
Limited impact if systems are properly segmented and access controlled, though the vulnerability remains exploitable if attackers gain network access.
🎯 Exploit Status
The vulnerability allows stack overwrite which typically leads to straightforward exploitation for code execution. No authentication is required to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 8.91 or later
Vendor Advisory: https://ics-cert.us-cert.gov/advisories/ICSA-17-213-01
Restart Required: Yes
Instructions:
1. Download Mitsubishi E-Designer Version 8.91 or later from Mitsubishi Electric. 2. Uninstall the vulnerable version 7.52 Build 344. 3. Install the updated version. 4. Restart the system. 5. Verify the installation by checking the version number.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Mitsubishi E-Designer systems from untrusted networks and implement strict network access controls.
Application Whitelisting
windowsImplement application whitelisting to prevent unauthorized execution of code on affected systems.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected systems from all untrusted networks
- Deploy host-based intrusion prevention systems (HIPS) with buffer overflow protection enabled
🔍 How to Verify
Check if Vulnerable:
Check the software version by opening Mitsubishi E-Designer and navigating to Help > About. If version is 7.52 Build 344, the system is vulnerable.Check Version:
Not applicable - check via GUI in Help > About menuVerify Fix Applied:
After patching, verify the version is 8.91 or later by checking Help > About in Mitsubishi E-Designer.📡 Detection & Monitoring
Log Indicators:
- Unexpected crashes of Mitsubishi E-Designer
- Unusual process creation from E-Designer executable
- Buffer overflow warnings in system logs
Network Indicators:
- Unusual network connections to/from E-Designer systems
- Traffic patterns indicating exploitation attempts
SIEM Query:
source="windows" AND (process_name="E-Designer.exe" AND event_id=1000) OR (process_name="E-Designer.exe" AND parent_process!="explorer.exe")