D-Link DIR 820lw Vulnerabilities
3 known CVEs, 2 critical, 1 in CISA's Known Exploited Vulnerabilities catalog. Last updated 2026-10-24.
Known CVEs
A Remote Command Execution (RCE) vulnerability exists in all series H/W revisions D-link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L routers via the DDNS function in ncc2 binary file. Note: DIR-810L, DIR-8...
D-Link DIR-820LW REVB FIRMWARE PATCH 2.03.B01_TC contains hardcoded credentials in the Telnet service, enabling attackers to log in remotely to the Telnet service and perform arbitrary commands.
A vulnerability was determined in D-Link DIR-820LW 2.03. Affected is the function ssdpcgi_main of the component SSDP. Executing a manipulation can lead to os command injection. The attack may be launched remotely. The...
Commonly exposed ports
- Port 23 (Telnet) — Sends admin credentials unencrypted — a common target on older router firmware.
- Port 80 (HTTP admin panel) — The web admin UI; dangerous if remote/WAN administration is left enabled.
- Port 7547 (TR-069 (CWMP)) — ISP remote-management protocol — has been the entry point for several router botnets.
- Port 1900 (UPnP/SSDP) — Lets apps on your LAN open firewall holes automatically, sometimes without your knowledge.
Default credentials
From ProbeShield's own tested default-credential list (see probeshield.com/default-passwords/): "admin" / "d-link" or "admin" / "pass" over HTTP.
Hardening checklist
- Disable remote (WAN-side) administration unless you specifically need it.
- Turn off UPnP unless a specific app you trust requires it.
- Turn off WPS — it can let an attacker bypass your Wi-Fi password.
- Change the default admin username and password to something unique.
- Check for a firmware update in the router’s admin panel and apply it.
- Disable Telnet/SSH management access if you don’t actively use it.
Frequently asked questions
Is my D-Link DIR 820lw affected by these vulnerabilities? Only if you’re running a firmware version in the affected range listed above and haven’t updated. Check your router's admin panel for its current firmware version and compare it against the ranges below.
How do I update my D-Link DIR 820lw's firmware? Log into the router's web admin panel (usually at its local IP address) and look for a Firmware Update or System Update section, or use the vendor's mobile app if it has one.
Does ProbeShield fix these vulnerabilities for me? No — ProbeShield scans your network and tells you what it finds (open ports, default credentials, outdated firmware signals) so you know what to fix, and how. It never changes your devices’ settings.
Sources: National Vulnerability Database (NVD), CISA Known Exploited Vulnerabilities Catalog. This page lists which firmware versions are affected — it doesn't claim your specific unit is vulnerable. Check your device's current firmware version in its admin panel and compare it against the ranges above.