An attacker can exploit a flaw in the etc/shadow.sample component of the D-Link DIR-1253 MESH firmware to gain elevated privileges within the device. The vulnerability permits escalation of authority from a lower‑privileged user context to full system control, allowing the attacker to alter configuration, install persistent malware, or disable security controls. The weakness maps to CWE‑269, indicating that the system fails to enforce proper privilege boundaries.

The issue affects D‑Link DIR‑1253 MESH devices running firmware version 1.6.1684. No other vendor or product variants are listed; the vulnerability appears specific to this model and firmware build.

EPSS score < 1% indicates a very low probability of exploitation. The CVSS score of 9.8 indicates a critical severity. The reported vulnerability could allow full control over the router, compromising network security and enabling further attacks against connected devices.