CVE-2021-39509: dlink dir-816_firmware Command Injection

Vulnerability summary

CVE-2021-39509 is a critical (CVSS 9.8) Command Injection vulnerability in dlink dir-816_firmware. EPSS estimates a 5.10% chance of exploitation in the next 30 days, higher than 92.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 24-08-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

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.

• CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.