CVE-2021-21820: D-Link Dir-3040 Firmware

Critical severity, CVSS 9.8. EPSS: 3% chance of exploitation in the next 30 days.

A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.

Affected products

• D-Link Dir-3040 Firmware: version 1.13b03 only

Published 2021-07-16. Last modified 2026-06-17.