PT-2026-36833 · D Link · Dir-605L

Arjun Basnet · Published 2026-04-20 · Updated 2026-05-06 · CVE-2026-42372

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

AV:A/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 A1

Description A hardcoded telnet backdoor exists where the device starts a telnet daemon at boot via the /bin/telnetd.sh script. The system uses a static username "Alphanetworks" and password "wrgn35 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 use these credentials 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:2026-06319

CVE-2026-42372

Affected Products

Dir-605L

References · 6

• 🔥 https://securin.io/zero-day/cve-2026-42372-hardcoded-telnet-backdoor-in-d-link-dir-605l-a1-end-of-life- · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-42372 · Security Note
• https://bdu.fstec.ru/vul/2026-06319 · Security Note
• https://t.me/cveNotify/162311 · Telegram Post
• https://t.me/CVEtracker/52638 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2051429254039056693 · Twitter Post