The wrong "handler" is assigned to process an object.
Extended description
An example of deploying the wrong handler would be calling a servlet to reveal source code of a .JSP file, or automatically "determining" type of the object even if it is contradictory to an explicitly specified type.
Best practices to prevent this CWE
Phase: Architecture and Design
Perform a type check before interpreting an object.
Phase: Architecture and Design
Reject any inconsistent types, such as a file with a .GIF extension that appears to consist of PHP code.