CVE-2024-1786 is a high severity (CVSS 7.5) buffer overflow in the Telnet service of the D-Link DIR-600M C1, firmware 3.08. The product is end of life, and D-Link says it should be retired and replaced. There is no patch to wait for, so replace the device.
What's affected
D-Link DIR-600M, hardware revision C1, firmware 3.08. The description is tagged UNSUPPORTED WHEN ASSIGNED, which means the CVE was issued for a product that no longer receives updates.
The vulnerable component is the Telnet service. The description says the username argument leads to a buffer overflow, and that the attack may be launched remotely. The weakness is CWE-120, a classic buffer copy without checking the size of input.
The record quotes the vendor: it confirmed the product is end of life and said it should be retired and replaced. So no fixed version will appear.
Severity conflict. The description text calls the issue critical. NVD scores it 7.5, which is High. Whichever label you use, the guidance is identical.
How to check if you're exposed
Log in to the router's admin page and read the model and firmware version, usually under System, Status or About. Compare it with the version named above.
You can also check from your own network without logging in, by looking at the device label for the model and revision, then matching it to the list above. Revision matters, because vendors often ship several hardware revisions under one model name.
Two more checks are worth doing on any consumer or small office router:
nmap -p 23,80,443,8080 192.168.0.1
Replace the address with your router's. If the management interface answers on a port you did not expect, or on the WAN side, that is a finding in its own right. Only scan devices you own or administer.
What to do now
- Identify every affected model on your network, including routers at remote offices and at employees' homes if you manage them.
- Check the vendor support page for a firmware release that names this CVE. The record says the vendor did not respond to the disclosure, so a fix may not exist.
- Turn off remote management on the WAN side and limit the admin interface to a trusted LAN segment or VLAN.
- Change the default admin password and make sure it is unique to the device.
- Disable the Telnet service in the router settings if the option exists, and use no remote management at all.
- If no fix is available and the device is exposed, plan to replace it with supported hardware.
Why it matters
Buffer overflows in a network service are dangerous because the service reads attacker supplied text, here a username, before login can succeed. Telnet adds a second problem: it sends everything, including passwords, in clear text, and it has no business being reachable from untrusted networks.
For an end of life product, the vulnerability is a symptom of a larger problem. Without vendor support, every new flaw stays open permanently. Replacing the device is the only complete fix.
A key takeaway for asset inventories is to track end of life dates for network gear as carefully as for software dependencies. Routers get forgotten in branch offices and homes of remote staff.
The record's Known Exploited Vulnerabilities flag is false.
Quick check
Will D-Link release a patch?
Not according to the record. The vendor confirmed the model is end of life and said it should be retired and replaced.
Can I mitigate without replacing it?
You can reduce exposure by disabling Telnet and remote management, but the device stays unsupported. Plan the replacement.
Sources
- NVD record for CVE-2024-1786
- VulDB entry 254576 (listed in the record, not retrievable when reviewed)
- Public write-up gist (listed in the record, not retrievable when reviewed)
Last reviewed: 19 October 2026.
