CVE-2019-25401
📋 TL;DR
This vulnerability allows remote attackers to crash the web service on Bematech MP-4200 TH printers by sending specially crafted POST requests to the admin configuration page. This causes a denial of service condition where the printer's web interface becomes unavailable. Organizations using these printers in retail, hospitality, or other point-of-sale environments are affected.
💻 Affected Systems
- Bematech MP-4200 TH thermal receipt printer
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Printer becomes completely unresponsive to network requests, requiring physical power cycle to restore functionality, disrupting business operations that depend on receipt printing.
Likely Case
Printer web interface crashes and becomes inaccessible, preventing remote configuration changes while printing functionality may continue working locally.
If Mitigated
Minimal impact if printers are isolated from untrusted networks and only accessible to authorized internal systems.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (47648) and requires only basic HTTP knowledge to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory found
Restart Required: No
Instructions:
No official patch available. Check with vendor (now Elgin) for firmware updates or replacement options.
🔧 Temporary Workarounds
Network Segmentation
allIsolate printer on separate VLAN with strict firewall rules blocking external access to port 80/443
Disable Web Interface
allTurn off HTTP/HTTPS administration interface if not required for operations
🧯 If You Can't Patch
- Implement strict network access controls allowing only trusted management systems to communicate with printer
- Monitor printer network traffic for malformed POST requests to /admin configuration endpoints
🔍 How to Verify
Check if Vulnerable:
Send crafted POST request to printer's admin page with malformed 'admin' and 'person' parameters and observe if web service crashesCheck Version:
Check printer firmware version via web interface or serial console if availableVerify Fix Applied:
Test with same exploit after implementing workarounds - web interface should remain accessible📡 Detection & Monitoring
Log Indicators:
- Web service crash logs
- Repeated failed POST requests to admin endpoints
- Printer service restart events
Network Indicators:
- HTTP POST requests with malformed parameters to /admin paths
- Sudden drop in printer web service responses
SIEM Query:
source="printer_logs" AND (http_method="POST" AND uri_path="/admin" AND (param="admin" OR param="person"))🔗 References
- https://web.archive.org/web/20180814065516/https://www.bematech.com.br/
- https://www.exploit-db.com/exploits/47648
- https://www.legacyglobal.com/products/bematech-formerly-logic-controls-mp-4200-thermal-receipt-printer/?srsltid=AfmBOor3LXakwJp10bE_8n8YIBKrFPFGFc5DKrxdMGChGQ-Y24i8MVQa
- https://www.vulncheck.com/advisories/bematech-printer-mp-th-denial-of-service
