Week 27 – Retire your D-Link DIR-816 router
30 June – 06 July 2025
Our CVE of the Week post brings you another fresh attack on a network device, but this time it affects owners of a D-Link DIR-816 wireless router, which is used in small home networks.
The router provides dual-band AC WiFi connectivity, 3G support, firewall capabilities, and promises additional security features like VPN access and content blocking.
While most of the time, consumer devices like this are set-and-forget as long as they are working, the recently discovered CVE-2025-5622 shows the importance of paying attention to security even in the smallest environments.
The exploit is a simple buffer overflow in the function “wirelessApcli_5g”, enabling unauthenticated attackers to take control of the device via crafted parameters (apcli_mode_5g, apcli_enc_5g, and apcli_default_key_5g) through the “/goform/wirelessApcli_5g” endpoint. Along with this advisory, several other critical flaws were discovered, tagged as CVE-2025-5623, CVE-2025-5624, and CVE-2025-5630, allowing similar attacks to take place.
Unfortunately, the DIR-816 is in End-of-Life status, meaning a patch will never be released. The only solution is to retire the device and upgrade to a newer model that continues to receive security updates. To future-proof your home network, we recommend looking at manufacturers and devices with a long support timeline and updating them regularly. Or, if you’re feeling a bit more technical, you can even roll your own home router with something like OPNSense or pfSense to ensure you are protected for a long time.
Technical details of the exploit: https://github.com/wudipjq/my_vuln/blob/main/D-Link5/vuln_50/50.md
NIST advisory: https://nvd.nist.gov/vuln/detail/cve-2025-5622#
D-Link product page: https://www.dlink.ru/mn/products/5/2212.html
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