Hard-Coded Credentials Vulnerability in LTSecurity LTK3500SF

LTSecurity LTK3500SF devices are vulnerable to a hard-coded credentials issue (CVE-2026-47116) where account passwords for 'root' and 'guest' users are stored as reversible hashes within the /etc/shadow file. This design flaw allows an attacker to extract the shadow file and employ standard dictionary-based cracking tools to recover plaintext credentials. Once compromised, these credentials permit unauthorized remote authentication via management protocols like Telnet or SSH. This vulnerability grants attackers complete control over the affected network appliance, enabling persistence, data exfiltration, or the ability to pivot deeper into the internal network environment.

Impact

Successful exploitation of CVE-2026-47116 results in a complete compromise of the LTSecurity LTK3500SF device. By gaining root-level access, attackers can modify system configurations, intercept network traffic, or use the device as a beachhead for further lateral movement within the victim's network. The severity is marked as critical due to the ease of credential recovery and the resulting administrative privileges provided to the attacker.

Recommendation

Prioritize the immediate restriction of management access to the affected devices.

• Restrict network access to Telnet and SSH ports on the LTK3500SF to trusted management subnets only.
• Implement a firewall policy to block unauthorized inbound connections to ports 22 and 23.
• Monitor logs for repeated failed authentication attempts followed by a successful login originating from unusual source IPs.
• Contact the vendor for firmware patches addressing the insecure storage of credentials in /etc/shadow.