CVE-2019-19840
📋 TL;DR
CVE-2019-19840 is a critical stack-based buffer overflow vulnerability in Ruckus Unleashed wireless controllers that allows remote code execution via unauthenticated HTTP requests. Attackers can exploit this to take complete control of affected devices. All Ruckus Unleashed systems through version 200.7.10.102.64 are vulnerable.
💻 Affected Systems
- Ruckus Unleashed Wireless Controllers
📦 What is this software?
Unleashed by Ruckuswireless
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install persistent backdoors, pivot to internal networks, steal credentials, and disrupt wireless services.
Likely Case
Remote code execution leading to device takeover, network reconnaissance, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict HTTP access controls and network segmentation.
🎯 Exploit Status
Public exploit code exists and has been demonstrated at security conferences. The vulnerability is easily exploitable with minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 200.7.10.102.64
Vendor Advisory: https://www.ruckuswireless.com/security/299/view/txt
Restart Required: Yes
Instructions:
1. Log into Ruckus Unleashed admin interface. 2. Navigate to System > Upgrade. 3. Download and install the latest firmware version. 4. Reboot the controller after installation completes.
🔧 Temporary Workarounds
Network Access Control
allRestrict HTTP access to Ruckus Unleashed controllers using firewall rules
VLAN Segmentation
allPlace Ruckus controllers on isolated management VLANs with strict access controls
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Ruckus controllers from untrusted networks
- Deploy intrusion prevention systems (IPS) with rules to detect and block exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version in Ruckus Unleashed admin interface under System > About. If version is 200.7.10.102.64 or earlier, the system is vulnerable.Check Version:
ssh admin@ruckus-controller 'show version' or check web interface at System > AboutVerify Fix Applied:
Verify firmware version is newer than 200.7.10.102.64 and check that the system is no longer responding to exploit attempts.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to zap.cgi endpoint
- Multiple failed buffer overflow attempts in system logs
- Unexpected process creation or system reboots
Network Indicators:
- HTTP POST requests to /cgi-bin/zap.cgi with abnormal payload sizes
- Traffic patterns matching known exploit signatures
SIEM Query:
source="ruckus-controller" AND (uri="/cgi-bin/zap.cgi" OR process="zap") AND (payload_size>1000 OR status_code=500)🔗 References
- https://alephsecurity.com/2020/01/14/ruckus-wireless
- https://fahrplan.events.ccc.de/congress/2019/Fahrplan/events/10816.html
- https://www.ruckuswireless.com/security/299/view/txt
- https://alephsecurity.com/2020/01/14/ruckus-wireless
- https://fahrplan.events.ccc.de/congress/2019/Fahrplan/events/10816.html
- https://www.ruckuswireless.com/security/299/view/txt
