CVE-2018-20440
📋 TL;DR
This vulnerability allows remote attackers to retrieve Wi-Fi credentials from affected Technicolor CWA0101 devices via specific SNMP requests. Attackers can obtain wireless network passwords without authentication, potentially compromising network security. This affects Technicolor CWA0101 CWA0101E-A23E-c7000r5712-170315-SKC devices.
💻 Affected Systems
- Technicolor CWA0101
📦 What is this software?
Cwa0101 Firmware by Technicolor
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain unauthorized access to the wireless network, potentially compromising all connected devices, intercepting sensitive data, and launching further attacks from within the network perimeter.
Likely Case
Attackers obtain Wi-Fi credentials and gain unauthorized network access, potentially leading to data theft, network reconnaissance, or lateral movement within the network.
If Mitigated
With proper SNMP access controls and network segmentation, the impact is limited to potential credential exposure without direct network access.
🎯 Exploit Status
Exploitation requires only SNMP access to the device and knowledge of the specific OIDs. The blog references provide technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Apply workarounds and consider device replacement if possible.
🔧 Temporary Workarounds
Disable SNMP
allCompletely disable SNMP service on affected devices to prevent credential retrieval.
Access device admin interface > Network > SNMP > Disable SNMP
Restrict SNMP Access
allConfigure SNMP to only allow access from trusted management IP addresses.
Access device admin interface > Network > SNMP > Configure ACLs to restrict access
Change Wi-Fi Credentials
allChange wireless network passwords after implementing SNMP controls.
Access device admin interface > Wireless > Security > Change WPA/WPA2 password
🧯 If You Can't Patch
- Isolate affected devices in a separate VLAN with strict network segmentation
- Implement network monitoring for SNMP requests to the vulnerable OIDs
🔍 How to Verify
Check if Vulnerable:
Test SNMP access to OIDs 1.3.6.1.4.1.4413.2.2.2.1.5.4.1.14.1.3.10001 and 1.3.6.1.4.1.4413.2.2.2.1.18.1.2.3.4.1.2.10001 using snmpwalk or similar tools.Check Version:
Check device admin interface or use SNMP to query system information OIDsVerify Fix Applied:
Verify SNMP is disabled or restricted, and test that the vulnerable OIDs no longer return Wi-Fi credentials.📡 Detection & Monitoring
Log Indicators:
- SNMP requests to the specific OIDs mentioned in CVE
- Unauthorized access attempts to SNMP service
Network Indicators:
- SNMP traffic to affected devices from untrusted sources
- Patterns of SNMP queries matching the vulnerable OIDs
SIEM Query:
source_ip=* AND destination_port=161 AND (oid="1.3.6.1.4.1.4413.2.2.2.1.5.4.1.14.1.3.10001" OR oid="1.3.6.1.4.1.4413.2.2.2.1.18.1.2.3.4.1.2.10001")