CAPEC-242 is a code injection attack pattern: an attacker supplies input that a program later treats as executable code. The core failure is not the code itself, but unsafe handling of data. When applications build commands, scripts, queries, or templates from untrusted input without strict validation and context-aware escaping, that input can change program behavior and trigger arbitrary execution.
This matters because code injection often turns a small input bug into full system compromise. In real attacks, it appears in web forms, management consoles, API parameters, and other interfaces where user-controlled data reaches an interpreter or runtime. Defenders reduce the risk with allowlists, parameterized APIs, output encoding, sandboxing, and least-privilege execution. In security appliances and admin tools, the impact can be especially severe because successful injection may expose the control plane, giving attackers direct access to critical configuration and device management.