CVE-2017-3216
📋 TL;DR
This vulnerability allows remote attackers to bypass authentication on WiMAX routers using MediaTek SDK's custom httpd plugin. Attackers can change the administrator password without credentials, gaining full device control. Affected devices include various WiMAX customer premises equipment (CPE) from multiple vendors.
💻 Affected Systems
- Various WiMAX CPE devices from multiple vendors using MediaTek SDK
📦 What is this software?
Ox350 Firmware by Greenpacket
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to reconfigure network settings, intercept traffic, install malware, or use device as pivot point into internal networks.
Likely Case
Unauthorized administrative access leading to network configuration changes, DNS hijacking, or device takeover for botnet participation.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering or in isolated network segments.
🎯 Exploit Status
Exploit involves simple crafted POST request to specific endpoint. Public technical details available in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Vendor-specific firmware updates
Vendor Advisory: http://www.kb.cert.org/vuls/id/350135
Restart Required: Yes
Instructions:
1. Check with device vendor for firmware updates. 2. Download latest firmware from vendor support site. 3. Upload firmware via admin interface. 4. Reboot device after update completes.
🔧 Temporary Workarounds
Network Segmentation
allIsolate WiMAX routers from critical internal networks
Access Control Lists
linuxRestrict management interface access to trusted IPs only
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Disable remote management interface if not required
- Change default admin credentials and monitor for unauthorized changes
🔍 How to Verify
Check if Vulnerable:
Test by attempting password change via POST request to vulnerable endpoint without authenticationCheck Version:
Check firmware version in router web interface or via ssh: cat /etc/versionVerify Fix Applied:
Attempt same exploit after patch - should receive authentication error📡 Detection & Monitoring
Log Indicators:
- Unauthorized POST requests to password change endpoints
- Admin password change events from unexpected IPs
Network Indicators:
- HTTP POST requests to router management interface from external IPs
- Traffic patterns suggesting device compromise
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/password.cgi" OR uri="*password*") AND status=200🔗 References
- http://blog.sec-consult.com/2017/06/ghosts-from-past-authentication-bypass.html
- http://www.kb.cert.org/vuls/id/350135
- https://sec-consult.com/fxdata/seccons/prod/temedia/advisories_txt/20170607-0_Various_WiMAX_CPEs_Authentication_Bypass_v10.txt
- http://blog.sec-consult.com/2017/06/ghosts-from-past-authentication-bypass.html
- http://www.kb.cert.org/vuls/id/350135
- https://sec-consult.com/fxdata/seccons/prod/temedia/advisories_txt/20170607-0_Various_WiMAX_CPEs_Authentication_Bypass_v10.txt
