Skip to content
Noroxi
CVE-2026-42373· NVD / CVE Program· CNA securin

D-Link DIR-605L B2 Hardcoded Telnet Backdoor Credentials

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.

HighCVSS 8.8 · v3.1—No exploit No fix recorded
Published
May 4, 2026
Updated
Jun 17, 2026
EPSS
1.0% · 61th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
8.8
CNA · securin
9.8
1.0 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Affected systems

VendorProduct
dlinkdir-605l firmware
dlinkdir-605l

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • dlink dir-605l firmwareall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (securin). Independent of NVD's CPE analysis and usually ahead of it.

  • D-Link DIR-605L Firmware

    • B2affected

Same product

dlink: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-40655An informtion disclosure issue exists in D-LINK-DIR-605 B2 Firmware Version : 2.01MT.KEV
    86Now
  • CVE-2025-4443D-Link DIR-605L sub_454F2C command injection
    39Monitor
  • CVE-2023-29961D-Link DIR-605L firmware version 1.17B01 BETA is vulnerable to stack overflow via /goform/formTcpipSetup,
    39Monitor
  • CVE-2023-24352D-Link N300 WI-FI Router DIR-605L v2.13B01 was discovered to contain a stack overflow via the webpage parameter at /goform/formWPS.
    39Monitor
  • CVE-2023-24351D-Link N300 WI-FI Router DIR-605L v2.13B01 was discovered to contain a stack overflow via the FILECODE parameter at /goform/formLogin.
    39Monitor
  • CVE-2023-24350D-Link N300 WI-FI Router DIR-605L v2.13B01 was discovered to contain a stack overflow via the config.smtp_email_subject parameter at /goform
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-423720 days apartD-Link DIR-605L A1 Hardcoded Telnet Backdoor Credentials
    35Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-798 · Use of Hard-coded Credentials

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

For convenience in support or manufacturing, an account that is identical on every device is embedded in the software. Credentials learned from one device work on all of them.

The bug in code

The whole CWE-798 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const SUPPORT_USER = "support";const SUPPORT_PASS = "hardcoded-password";

Fixed

ts
const creds = await provisioning.deviceCredentials(deviceId);if (creds.mustRotate) await forcePasswordChange(deviceId);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

All records