Technical impact
The vulnerability is a stack‑based buffer overflow triggered by the sprintf function in the yyxz.asp page of D‑Link DI‑8100 routers. By manipulating the ID argument, an attacker can overflow the stack and overwrite control data. This type of flaw is inferred to enable arbitrary code execution because the overflow can overwrite return addresses or other critical control structures, thereby allowing the attacker to run malicious code on the device. The impact therefore includes potential compromise of the router’s confidentiality, integrity and availability. The flaw is classified as CWE‑119 and CWE‑121.
Affected Systems
D‑Link DI‑8100 routers running firmware version 16.07.26A1. No other D‑Link routers or firmware versions are listed as affected. The vulnerable code resides in the yyxz.asp page delivered by the firmware image.
Risk and Exploitability
The CVSS score of 8.6 denotes a high‑severity vulnerability, while the EPSS score of 4% indicates a low but non‑zero probability of exploitation. The exploit is documented as publicly available, so the risk to any router that exposes its web administration interface is significant. The attack vector is inferred to be remote, as the vulnerability can be triggered over the WAN interface by sending a crafted request to yyxz.asp with an attacker‑controlled ID parameter. Because no authentication is required and the vulnerability is fully remote, the broader network could be jeopardised if the router is not protected.
