PT-2026-36834 · D Link · Dir-605L

Arjun Basnet · Published 2026-04-20 · Updated 2026-05-13 · CVE-2026-42373

Positive Technologies (AI Summary)

CVSS v3.1

10

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions D-Link DIR-605L Hardware Revision B2

Description A hardcoded telnet backdoor exists where the device starts a telnet daemon at boot via the /bin/telnetd.sh script. The system uses the username "Alphanetworks" and a static password "wrgn76 dlwbr dir605L" stored in /etc/alpha config/image sign. The custom telnetd binary utilizes a -u user:password flag, and the login binary employs the strcmp() function to validate credentials. An unauthenticated attacker on the local network can exploit this to gain a root shell with full administrative control.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Using Hardcoded Credentials

Weakness Enumeration

CWE-798

CWE-259

Related Identifiers

BDU:2026-06320

CVE-2026-42373

Affected Products

Dir-605L

References · 9

• 🔥 https://securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life- · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-42373 · Security Note
• https://bdu.fstec.ru/vul/2026-06320 · Security Note
• https://twitter.com/lyrie_ai/status/2054440745310765265 · Twitter Post
• https://twitter.com/lyrie_ai/status/2054440746279707004 · Twitter Post
• https://t.me/CVEtracker/52639 · Telegram Post
• https://twitter.com/lyrie_ai/status/2054440747126935878 · Twitter Post
• https://t.me/cveNotify/162312 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2051426694188163132 · Twitter Post