CVE-2020-21995
📋 TL;DR
Inim Electronics Smartliving SmartLAN/G/SI devices up to version 6.x use hardcoded default credentials, allowing attackers to gain Telnet, SSH, and FTP access. This affects all systems running vulnerable firmware versions. Attackers can fully compromise affected devices using these known credentials.
💻 Affected Systems
- Inim Electronics Smartliving SmartLAN/G/SI
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install malware, pivot to internal networks, disrupt operations, or use devices for botnets.
Likely Case
Unauthorized access leading to data theft, configuration changes, service disruption, and lateral movement within networks.
If Mitigated
Limited impact if devices are isolated, credentials changed, or access controls prevent exploitation.
🎯 Exploit Status
Exploitation requires only knowledge of default credentials. Public exploit code demonstrates access methods.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
1. Contact Inim Electronics for firmware updates or security guidance. 2. If updates exist, download from official vendor sources. 3. Apply firmware update following vendor instructions.
🔧 Temporary Workarounds
Change Default Credentials
allImmediately change all default Telnet, SSH, and FTP credentials to strong, unique passwords.
telnet <device_ip> (login with default creds)
passwd (change password)
Repeat for SSH and FTP services if accessible
Disable Unnecessary Services
allDisable Telnet, SSH, and FTP services if not required for operations.
Check device configuration interface for service management
Disable Telnet/SSH/FTP if possible
🧯 If You Can't Patch
- Network segmentation: Isolate affected devices in separate VLANs with strict firewall rules.
- Access control: Implement IP whitelisting for management interfaces and disable external access.
🔍 How to Verify
Check if Vulnerable:
Attempt to connect via Telnet/SSH/FTP using known default credentials (check exploit references). Successful login indicates vulnerability.Check Version:
Check device web interface or use vendor-specific commands to display firmware version.Verify Fix Applied:
Verify default credentials no longer work and new strong credentials are required. Confirm services are disabled or properly secured.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful logins with default usernames
- Multiple Telnet/SSH/FTP connections from unusual sources
Network Indicators:
- Telnet/SSH/FTP traffic to device management ports from unauthorized IPs
- Unusual outbound connections from device after compromise
SIEM Query:
source="device_logs" (event_type="authentication" AND (username="default" OR username="admin") AND result="success")