CVE-2026-42373

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life-	Exploit Third Party Advisory
https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life-	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

AND

cpe:2.3:o:dlink:dir-605l_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:dlink:dir-605l:b2:*:*:*:*:*:*:*

History

06 May 2026, 12:19

Type	Values Removed	Values Added
First Time		Dlink dir-605l Dlink Dlink dir-605l Firmware
References	~~() https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life- -~~	() https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life- - Exploit, Third Party Advisory
CPE		cpe:2.3:h:dlink:dir-605l:b2:::::::* cpe:2.3:o:dlink:dir-605l_firmware::::::::

04 May 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-04 17:16

Updated : 2026-05-06 12:19

NVD link : CVE-2026-42373

Mitre link : CVE-2026-42373

CVE.ORG link : CVE-2026-42373

JSON object : View

Products Affected

dlink

dir-605l
dir-605l_firmware

CWE

CWE-798

Use of Hard-coded Credentials

{"id": "CVE-2026-42373", "cveTags": [{"tags": ["unsupported-when-assigned"], "sourceIdentifier": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"}], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}]}, "published": "2026-05-04T17:16:25.527", "references": [{"url": "https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life-", "tags": ["Exploit", "Third Party Advisory"], "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"}, {"url": "https://www.securin.io/zero-day/cve-2026-42373-hardcoded-telnet-backdoor-in-d-link-dir-605l-b2-end-of-life-", "tags": ["Exploit", "Third Party Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c", "description": [{"lang": "en", "value": "CWE-798"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-05-06T12:19:20.757", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:dlink:dir-605l_firmware:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "38A73373-86B3-4DDC-A880-A66D29C7176F"}], "operator": "OR"}, {"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:h:dlink:dir-605l:b2:*:*:*:*:*:*:*", "vulnerable": false, "matchCriteriaId": "D096BA86-3FCB-4F16-89CA-3A2A152C88B9"}], "operator": "OR"}], "operator": "AND"}], "sourceIdentifier": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"}