CVE-2019-9835
📋 TL;DR
This vulnerability allows attackers to inject keystrokes into Fujitsu Wireless Keyboard Set LX901 GK900 devices by sending unencrypted 2.4 GHz packets that the receiver accepts despite legitimate communication using AES encryption. This affects users of these specific wireless keyboard sets, allowing attackers within wireless range to execute arbitrary commands on connected systems.
💻 Affected Systems
- Fujitsu Wireless Keyboard Set LX901 GK900
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through arbitrary command execution, data theft, malware installation, or lateral movement within the network.
Likely Case
Local privilege escalation, credential theft, or installation of backdoors on affected systems within wireless range.
If Mitigated
Limited impact if devices are physically secured, wireless range is controlled, or systems have additional authentication layers.
🎯 Exploit Status
Exploitation requires proximity to wireless receiver and ability to transmit on 2.4 GHz frequency. No authentication or special privileges needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
Contact Fujitsu support for firmware updates or replacement options. No official patch documentation available.
🔧 Temporary Workarounds
Physical Isolation
allPlace wireless receiver in physically secure location with limited wireless range
Replace with Wired Keyboard
allReplace vulnerable wireless keyboard with wired alternative
🧯 If You Can't Patch
- Deploy in physically secure environments with controlled access
- Implement additional authentication layers on connected systems
- Monitor for unusual keyboard activity or unexpected commands
- Consider using USB port blockers when not in use
🔍 How to Verify
Check if Vulnerable:
Check device model number (LX901 GK900) and test with wireless packet analyzer for unencrypted packet acceptanceCheck Version:
No standard command - check device labeling or firmware via manufacturer toolsVerify Fix Applied:
Test with wireless security tools to confirm only encrypted packets are accepted📡 Detection & Monitoring
Log Indicators:
- Unexpected command execution, rapid keystroke sequences, or administrative commands from non-privileged sessions
Network Indicators:
- 2.4 GHz wireless traffic patterns inconsistent with normal keyboard usage
SIEM Query:
Search for: (rapid keyboard input) OR (unexpected administrative commands) OR (suspicious timing of keyboard events)