CVE-2026-42374

HIGH
MEDIUM Priority: 0.04 BB Relevance: 63/100
Published: 2026-05-04 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Adjacent
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: High
A: High

Description

D-Link DIR-600L Hardware Revision B1 (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 "wrgn61_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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
dlink dir-600l_firmware *

Bug Bounty Relevance

63 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.8 / 10.0 v3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.47%
Raw Score 0.004720
Percentile 40.8%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00472
2026-10-28
0.00472

Intelligence Sources

nvd ref →