CVE-2026-42373: D-Link DIR-605L B2 Hardcoded Telnet Backdoor Credentials
D-Link DIR-605L Hardware Revision B2 (End-of-Life, EOL) 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 "wrgn76dlwbrdir605L" read from /etc/alphaconfig/imagesign. 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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42373?
CVE-2026-42373 is classified as critical due to the presence of a hardcoded telnet backdoor.
How do I fix CVE-2026-42373?
The best mitigation for CVE-2026-42373 is to discontinue the use of the affected D-Link DIR-605L Hardware Revision B2 device.
What are the risks associated with CVE-2026-42373?
CVE-2026-42373 poses significant risks as it allows unauthorized remote access to the device using hardcoded credentials.
Is the D-Link DIR-605L Hardware Revision B2 still supported after CVE-2026-42373?
The D-Link DIR-605L Hardware Revision B2 is classified as End-of-Life (EOL) and is no longer supported, making it more vulnerable.
What is the default username and password for CVE-2026-42373?
The default username is 'Alphanetworks' and the password is 'wrgn76_dlwbr_dir605L'.