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4 vulnerabilities found for DIR-600L Firmware by D-Link
CVE-2026-42375 (GCVE-0-2026-42375)
Vulnerability from nvd – Published: 2026-05-04 16:02 – Updated: 2026-05-05 12:43 Unsupported When Assigned
VLAI
Title
D-Link DIR-600L A1 Hardcoded Telnet Backdoor Credentials
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-798 - Use of Hard-coded Credentials
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| D-Link | DIR-600L Firmware |
Affected:
A1
(custom)
cpe:2.3:o:dlink:dir-600l_firmware:*:*:*:*:*:*:*:* |
Date Public
2026-04-24 00:00
Credits
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CVE-2026-42374 (GCVE-0-2026-42374)
Vulnerability from nvd – Published: 2026-05-04 16:00 – Updated: 2026-05-05 12:43 Unsupported When Assigned
VLAI
Title
D-Link DIR-600L B1 Hardcoded Telnet Backdoor Credentials
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-798 - Use of Hard-coded Credentials
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| D-Link | DIR-600L Firmware |
Affected:
B1
(custom)
cpe:2.3:o:dlink:dir-600l_firmware:*:*:*:*:*:*:*:* |
Date Public
2026-04-24 00:00
Credits
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CVE-2026-42375 (GCVE-0-2026-42375)
Vulnerability from cvelistv5 – Published: 2026-05-04 16:02 – Updated: 2026-05-05 12:43 Unsupported When Assigned
VLAI
Title
D-Link DIR-600L A1 Hardcoded Telnet Backdoor Credentials
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-798 - Use of Hard-coded Credentials
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| D-Link | DIR-600L Firmware |
Affected:
A1
(custom)
cpe:2.3:o:dlink:dir-600l_firmware:*:*:*:*:*:*:*:* |
Date Public
2026-04-24 00:00
Credits
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CVE-2026-42374 (GCVE-0-2026-42374)
Vulnerability from cvelistv5 – Published: 2026-05-04 16:00 – Updated: 2026-05-05 12:43 Unsupported When Assigned
VLAI
Title
D-Link DIR-600L B1 Hardcoded Telnet Backdoor Credentials
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-798 - Use of Hard-coded Credentials
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| D-Link | DIR-600L Firmware |
Affected:
B1
(custom)
cpe:2.3:o:dlink:dir-600l_firmware:*:*:*:*:*:*:*:* |
Date Public
2026-04-24 00:00
Credits
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"version": "B1",
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"value": "\u003cp\u003eD-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.\u0026nbsp; The device has reached End-of-Life (EOL) and will not receive patches.\u003c/p\u003e"
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}
],
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"description": "CWE-798 Use of Hard-coded Credentials",
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"name": "D-Link DIR-600L B1 Hardcoded Telnet Backdoor - Securin Advisory",
"url": "https://www.securin.io/zero-day/cve-2026-42374-hardcoded-telnet-backdoor-in-d-link-dir-600l-b1-end-of-life-"
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"title": "D-Link DIR-600L B1 Hardcoded Telnet Backdoor Credentials",
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"value": "\u003cp\u003eThis product is End-of-Life (EOL) and will NOT receive patches. Users should replace the device. Temporary: connect via backdoor and run \"killall telnetd\" and \"iptables -A INPUT -p tcp --dport 23 -j DROP\" (lost on reboot).\u003c/p\u003e"
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"value": "This product is End-of-Life (EOL) and will NOT receive patches. Users should replace the device. Temporary: connect via backdoor and run \"killall telnetd\" and \"iptables -A INPUT -p tcp --dport 23 -j DROP\" (lost on reboot)."
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