CVE-2021-39509: D-Link Dir-816 Firmware

Critical severity, CVSS 9.8. EPSS: 5.1% chance of exploitation in the next 30 days.

An issue was discovered in D-Link DIR-816 DIR-816A2_FWv1.10CNB05_R1B011D88210 The HTTP request parameter is used in the handler function of /goform/form2userconfig.cgi route, which can construct the user name string to delete the user function. This can lead to command injection through shell metacharacters.

Affected products

• D-Link Dir-816 Firmware: version 1.10cnb05_r1b011d88210 only

Published 2021-08-24. Last modified 2026-06-17.