Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:U) | Scope unchanged |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:H) | High integrity impact |
| Availability (A:H) | High availability impact |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
About Dlink Dir-605l Firmware
CVE-2026-42373 affects Dlink Dir-605l Firmware, a product from Dlink. Before acting, confirm where Dlink Dir-605l Firmware runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: 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.
The weakness class is Hard Coded Credentials. A password or key is built into the software.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Dlink Dir-605l Firmware |
| Affected versions | Dir-605l Firmware all listed versions |
| Published | May 4, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | 33c584b5-0579-4c06-b2a0-8d8329fcab9c |
How to detect it
- Inventory every instance of Dlink Dir-605l Firmware and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Dlink Dir-605l Firmware named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Dlink Dir-605l Firmware to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-798: Hard Coded Credentials More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
A vulnerability was detected in D-Link DI-7001 MINI up to 19.09.19A1. Impacted is the function sprintf of the file /httpd_debug.asp of the component API. The manipulation of the argument Time results in stack-based buffer overflow. The attack may be performed from remote. The exploit is now public and may be used.
A vulnerability was detected in D-Link DI-8100 16.07.26A1. Affected by this issue is the function tggl_asp of the file /tggl.asp of the component HTTP Request Handler. Performing a manipulation of the argument Name results in buffer overflow. The attack can be initiated remotely. The exploit is now public and may be used.
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.
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.
A vulnerability was found in D-Link DI-8100 16.07.26A1. This affects the function tgfile_htm of the file tgfile.htm of the component CGI Endpoint. The manipulation of the argument fn results in buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used.
A buffer overflow vulnerability exists in D-Link DI-8003 16.07.26A1 due to improper validation of the id parameter in the /thd_member.asp endpoint.
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