The software 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.
Command injection vulnerabilities typically occur when:
1. Data enters the application from an untrusted source.
2. The data is part of a string that is executed as a command by the application.
3. By executing the command, the application gives an attacker a privilege or capability that the attacker would not otherwise have.
Command injection is a common problem with wrapper programs.
If a malicious user injects a character (such as a semi-colon) that delimits the end of one command and the beginning of another, it may be possible to then insert an entirely new and unrelated command that was not intended to be executed.
The weakness is introduced during Architecture and Design, Implementation stages.
Latest vulnerabilities for CWE-77
Description of CWE-77 on Mitre website