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 "wrgn76_dlwbr_dir605L" 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.

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Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

This product is End-of-Life (EOL) and will NOT receive patches. Users should replace the device. Temporary: connect via backdoor and run "killall telnetd" and "iptables -A INPUT -p tcp --dport 23 -j DROP" (lost on reboot).

History

Mon, 04 May 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared D-link
D-link dir-605l Firmware
Vendors & Products D-link
D-link dir-605l Firmware

Mon, 04 May 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 04 May 2026 16:30:00 +0000

Type Values Removed Values Added
Description 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 "wrgn76_dlwbr_dir605L" 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.
Title D-Link DIR-605L B2 Hardcoded Telnet Backdoor Credentials
First Time appeared Dlink
Dlink dir-605l Firmware
Weaknesses CWE-798
CPEs cpe:2.3:o:dlink:dir-605l_firmware:*:*:*:*:*:*:*:*
Vendors & Products Dlink
Dlink dir-605l Firmware
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: securin

Published:

Updated: 2026-05-04T16:34:37.195Z

Reserved: 2026-04-27T06:21:56.901Z

Link: CVE-2026-42373

cve-icon Vulnrichment

Updated: 2026-05-04T16:34:26.999Z

cve-icon NVD

Status : Received

Published: 2026-05-04T17:16:25.527

Modified: 2026-05-04T17:16:25.527

Link: CVE-2026-42373

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-04T17:30:04Z

Weaknesses