CVE-2026-42375
CriticalSummary
D-Link DIR-600L Hardware Revision A1 contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot with the default username 'Alphanetworks' and static password 'wrgn35_dlwbr_dir600l'.
Risk Assessment
An attacker on the local network can gain root shell access with full administrative control, posing a serious security threat to the organization.
Recommendation
It is recommended to immediately disable the device and consider replacing it with a model that receives security updates.
Original NVD description (English source)
D-Link DIR-600L Hardware Revision A1 (End-of-Life) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /bin/telnetd.sh with the username "Alphanetworks" and the static password "wrgn35_dlwbr_dir600l" read from /etc/alpha_config/image_sign. The custom telnetd binary accepts a -u user:password flag, and the custom login binary uses strcmp() to validate credentials. Successful authentication grants an unauthenticated attacker on the local network a root shell with full administrative control. The device has reached End-of-Life (EOL) and will not receive patches.