Improper Neutralization of Escape, Meta, or Control Sequences

Think of this flaw as a broken translation step in data processing. When an application receives input—like a filename, a database query, or a command argument—it must treat special characters (like newlines, escape codes, or terminal control sequences) as literal data, not as instructions. If the application doesn't correctly neutralize these sequences, the downstream component (e.g., a shell, parser, or terminal) will misinterpret them, executing unintended commands or altering the program's expected flow. In practice, this often manifests when delimiters are missing, malformed, or injected by an attacker. For example, an unescaped newline in a log file could be interpreted as a command separator, or a crafted escape sequence could clear a terminal screen or manipulate output. To prevent this, developers must explicitly define and validate data boundaries, ensuring all special control characters are escaped or encoded according to the specific context of the receiving component.