CVE-2019-18242
📋 TL;DR
This vulnerability in Moxa ioLogik 2500 series devices allows denial of service attacks through web server crashes when receiving frequent multiple requests. It affects industrial control systems using these devices with vulnerable firmware and configuration utilities.
💻 Affected Systems
- Moxa ioLogik 2500 series
- IOxpress configuration utility
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service preventing remote management and monitoring of industrial equipment, potentially disrupting operations.
Likely Case
Temporary web server crashes requiring manual intervention to restore management access.
If Mitigated
Limited impact with proper network segmentation and access controls preventing external exploitation.
🎯 Exploit Status
Simple HTTP request flooding can trigger the vulnerability without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: ioLogik 2500 firmware Version 3.1 or higher, IOxpress Version 2.4.0 or higher
Vendor Advisory: https://www.moxa.com/en/support/product-support/security-advisory/moxa-io-logik-2500-series-web-server-vulnerability
Restart Required: Yes
Instructions:
1. Download latest firmware from Moxa website. 2. Backup current configuration. 3. Upload and install new firmware via web interface. 4. Update IOxpress utility to latest version. 5. Verify functionality after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate ioLogik devices on separate VLAN with strict firewall rules limiting HTTP access.
Rate Limiting
allImplement network-level rate limiting for HTTP requests to ioLogik devices.
🧯 If You Can't Patch
- Implement strict network access controls allowing only trusted IPs to access web interface
- Disable web interface if not required and use alternative management methods
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface: System > About. Verify version is 3.0 or lower.Check Version:
No CLI command - check via web interface or IOxpress utilityVerify Fix Applied:
Confirm firmware version is 3.1 or higher and test web server stability under normal load.📡 Detection & Monitoring
Log Indicators:
- Web server crash logs
- Multiple rapid HTTP requests from single source
- Service restart events
Network Indicators:
- High volume of HTTP requests to port 80/443
- Requests with abnormal patterns
SIEM Query:
source_ip=* AND dest_port=80 AND request_count>1000 WITHIN 60s