CVE-2026-42374
published 2026-05-04CVE-2026-42374: 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…
PriorityP357high8.8CVSS 3.1
AVAACLPRNUINSUCHIHAH
EPSS
0.47%
37.8th percentile
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.
Affected
1 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| d-link | dir-600l_firmware | — | — |
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VulDB
D-Link DIR-600L B1 /bin/telnetd.sh strcmp hard-coded credentials (EUVD-2026-27025)
vuldb·2026-05-04·CVSS 9.8
CVE-2026-42374 [CRITICAL] D-Link DIR-600L B1 /bin/telnetd.sh strcmp hard-coded credentials (EUVD-2026-27025)
A vulnerability described as critical has been identified in D-Link DIR-600L B1. Affected by this issue is the function strcmp of the file /bin/telnetd.sh. Executing a manipulation can lead to hard-coded credentials. This vulnerability only affects products that are no longer supported by the maintainer.
This vulnerability appears as CVE-2026-42374. The attacker needs to be present on the local network. There is no available exploit.
GHSA
GHSA-qcvh-q94p-mxjx: D-Link DIR-600L Hardware Revision B1 (End-of-Life) contains a hardcoded telnet backdoor
ghsa_unreviewed·2026-05-04
CVE-2026-42374 [CRITICAL] CWE-798 GHSA-qcvh-q94p-mxjx: D-Link DIR-600L Hardware Revision B1 (End-of-Life) contains a hardcoded telnet backdoor
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.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-05-04
Published