CVE-2026-42375

HIGH EPSS 37.4%
Published May 4, 20261mo ago · Modified Jun 17, 20261w ago
8.8 CVSS 3.1
High
Find Similar
Published May 4, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago

Description

D-Link DIR-600L Hardware Revision A1 (End-of-Life) 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 "wrgn35_dlwbr_dir600l" 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.

CVSS Details

Base Score
8.8
Exploitability
2.8
Impact
5.9
Vector string
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Adjacent
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
37.4% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-798 Use of Hard-coded Credentials Authentication

Affected Products 2

VendorProductVersionRange
dlinkdir-600l_firmware*any
dlinkdir-600la1any

References 1

  • securin.io https://www.securin.io/zero-day/cve-2026-42375-hardcoded-telnet-backdoor-in-d-link-dir-600l-a1-end-of-life-
    ExploitThird Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.