CVE-2026-42373: CWE-798 Use of Hard-coded Credentials in D-Link DIR-605L Firmware
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.
AI Analysis
Technical Summary
CVE-2026-42373 identifies a critical vulnerability in the D-Link DIR-605L B2 firmware where a hardcoded telnet backdoor exists. The device starts a telnet daemon at boot with a fixed username 'Alphanetworks' and password 'wrgn76_dlwbr_dir605L' stored in a configuration file. The custom telnet daemon and login binaries perform simple string comparison for authentication, enabling an unauthenticated attacker on the local network to obtain root shell access. This vulnerability is classified under CWE-798 (Use of Hard-coded Credentials). The device is End-of-Life and no official patches or fixes are available.
Potential Impact
An unauthenticated attacker on the local network can exploit this vulnerability to gain root-level access to the affected device. This grants full administrative control, allowing potential compromise of device functionality, network traffic interception, or further lateral movement within the network. Since the device is End-of-Life, no vendor patches or official fixes will be provided, leaving the vulnerability unmitigated by updates.
Mitigation Recommendations
No official patch or fix is available due to the device's End-of-Life status. Mitigation should focus on network-level controls such as isolating the affected device from untrusted networks, disabling telnet access if possible, or replacing the device with a supported model that does not contain this vulnerability.
CVE-2026-42373: CWE-798 Use of Hard-coded Credentials in D-Link DIR-605L Firmware
Description
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-42373 identifies a critical vulnerability in the D-Link DIR-605L B2 firmware where a hardcoded telnet backdoor exists. The device starts a telnet daemon at boot with a fixed username 'Alphanetworks' and password 'wrgn76_dlwbr_dir605L' stored in a configuration file. The custom telnet daemon and login binaries perform simple string comparison for authentication, enabling an unauthenticated attacker on the local network to obtain root shell access. This vulnerability is classified under CWE-798 (Use of Hard-coded Credentials). The device is End-of-Life and no official patches or fixes are available.
Potential Impact
An unauthenticated attacker on the local network can exploit this vulnerability to gain root-level access to the affected device. This grants full administrative control, allowing potential compromise of device functionality, network traffic interception, or further lateral movement within the network. Since the device is End-of-Life, no vendor patches or official fixes will be provided, leaving the vulnerability unmitigated by updates.
Mitigation Recommendations
No official patch or fix is available due to the device's End-of-Life status. Mitigation should focus on network-level controls such as isolating the affected device from untrusted networks, disabling telnet access if possible, or replacing the device with a supported model that does not contain this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- securin
- Date Reserved
- 2026-04-27T06:21:56.901Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69f8cb08cbff5d86103668b7
Added to database: 5/4/2026, 4:36:24 PM
Last enriched: 5/4/2026, 4:51:50 PM
Last updated: 5/5/2026, 5:56:37 AM
Views: 7
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