The vulnerability of the telnetd.sh script of the D-Link DIR-456U router’s telnet service allows a hacker to gain unauthorized access to protected information, increase their privileges, and execute arbitrary commands.

The vulnerability of the telnetd.sh script of the D-Link DIR-456U router’s telnet service is related to the use of a static password, whdrv01dlobdir456U, for the Alphanetworks account. Exploiting this vulnerability can allow an attacker to gain unauthorized access to protected information, enhanc...

CVE-2026-42376

D-Link DIR-456U Hardware Revision A1 End-of-Life, EOL contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /etc/init0.d/S80telnetd.sh with the username "Alphanetworks" and the static password "whdrv01dlobdir456U" read from /etc/config/imagesign. The custom telnetd...

EUVD-2026-27029

D-Link DIR-456U Hardware Revision A1 End-of-Life, EOL contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /etc/init0.d/S80telnetd.sh with the username "Alphanetworks" and the static password "whdrv01dlobdir456U" read from /etc/config/imagesign. The custom telnetd...

CVE-2026-42376 D-Link DIR-456U A1 Hardcoded Telnet Backdoor Credentials

D-Link DIR-456U Hardware Revision A1 End-of-Life, EOL contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /etc/init0.d/S80telnetd.sh with the username "Alphanetworks" and the static password "whdrv01dlobdir456U" read from /etc/config/imagesign. The custom telnetd...

CVE-2026-42376

CVE-2026-42376 affects D-Link DIR-456U hardware revision A1 (End-of-Life). The description reports a hardcoded telnet backdoor: at boot a telnet daemon runs with username “Alphanetworks” and password read from /etc/config/image_sign; a -u user:password flag is accepted by the custom telnetd, and ...

PT-2026-36837

Name of the Vulnerable Software and Affected Versions D-Link DIR-456U Hardware Revision A1 Description The device contains a hardcoded telnet backdoor. At boot, a telnet daemon is started via the script '/etc/init0.d/S80telnetd.sh' using the username "Alphanetworks" and a static password "whdrv01...