Remote Stack-Based Buffer Overflow in D-Link DI-8400

A security vulnerability identified as CVE-2026-101081 affects the D-Link DI-8400 router running firmware version 16.07. The flaw resides within the Web Administration Service component, specifically in the 'menu_nat_more_asp' function handled by the 'menu_nat_more.asp' file. By sending a crafted HTTP request that manipulates the 'opt' argument, an unauthenticated remote attacker can trigger a stack-based buffer overflow. This vulnerability carries a CVSS 3.1 base score of 9.1, indicating a high risk of remote code execution. Public exploit code has been released, increasing the likelihood of opportunistic exploitation in the wild. Defenders should prioritize restricting access to the web administration interface of these devices or applying manufacturer updates if available.

Impact

Successful exploitation of this vulnerability allows an unauthenticated remote attacker to gain control over the affected D-Link DI-8400 router. This can lead to full system compromise, persistent unauthorized access, or the use of the device as a pivot point for further lateral movement within the network. Given the public availability of the exploit, all exposed D-Link DI-8400 devices are at high risk of being targeted.

Recommendation

• Restrict network access to the D-Link DI-8400 Web Administration Service to known, trusted management IP addresses.
• Disable remote access to the administration interface if not strictly required.
• Implement network-based intrusion detection signatures to identify HTTP requests containing oversized payloads targeting the 'menu_nat_more.asp' endpoint.
• Monitor logs for unusual access attempts to administrative pages on network infrastructure devices.