D-Link DIR-456U A1 Hardcoded Telnet Backdoor Credentials
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| D-Link | DIR-456U Firmware | affected |
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Configuration 1 [-]
| AND |
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No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| D-link | Dir-456u Firmware |
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Vendor Workaround
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).
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.461% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Dlink dir-456u
|
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| CPEs | cpe:2.3:h:dlink:dir-456u:a1:*:*:*:*:*:*:* cpe:2.3:o:dlink:dir-456u_firmware:-:*:*:*:*:*:*:* |
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| Vendors & Products |
Dlink dir-456u
|
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
D-link
D-link dir-456u Firmware |
|
| Vendors & Products |
D-link
D-link dir-456u Firmware |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
| Type | Values Removed | Values Added |
|---|---|---|
| Description | D-Link DIR-456U Hardware Revision A1 (End-of-Life, EOL) contains a hardcoded telnet backdoor. The device starts a telnet daemon at boot via /etc/init0.d/S80telnetd.sh with the username "Alphanetworks" and the static password "whdrv01_dlob_dir456U" read from /etc/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. | |
| Title | D-Link DIR-456U A1 Hardcoded Telnet Backdoor Credentials | |
| First Time appeared |
Dlink
Dlink dir-456u Firmware |
|
| Weaknesses | CWE-798 | |
| CPEs | cpe:2.3:o:dlink:dir-456u_firmware:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Dlink
Dlink dir-456u Firmware |
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| References |
| |
| Metrics |
cvssV3_1
|