CVE-2026-42376: D-Link DIR-456U Firmware, заобикаляне на вход и права

Описание

Оригинално описание

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 "whdrv01_dlob_dir456U" read from /etc/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.

Засегнати продукти

• D-Link DIR-456U Firmware: A1

Вид слабост

• CWE-798 Use of Hard-coded Credentials

История

Първоизточници

• https://www.cve.org/CVERecord?id=CVE-2026-42376
• https://nvd.nist.gov/vuln/detail/CVE-2026-42376
• https://www.securin.io/zero-day/cve-2026-42376-hardcoded-telnet-backdoor-in-d-link-dir-456u-a1-end-of-life-