Data Validation Issues

Weaknesses in this category are related to a software system's components for input validation, output validation, or other kinds of validation. Validation is a frequently-used technique for ensuring that data conforms to expectations before it is further processed as input or output. There are many varieties of validation (see CWE-20, which is just for input validation). Validation is distinct from other techniques that attempt to modify data before processing it, although developers may consider all attempts to product "safe" inputs or outputs as some kind of validation. Regardless, validation is a powerful tool that is often used to minimize malformed data from entering the system, or indirectly avoid code injection or other potentially-malicious patterns when generating output. The weaknesses in this category could lead to a degradation of the quality of data flow in a system if they are not addressed.