The wrong "handler" is assigned to process an object.
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.
Perform a type check before interpreting an object.
Reject any inconsistent types, such as a file with a .GIF extension that appears to consist of PHP code.
CVE-2001-0004Source code disclosure via manipulated file extension that causes parsing by wrong DLL.
CVE-2002-0025Web browser does not properly handle the Content-Type header field, causing a different application to process the document.
CVE-2000-1052Source code disclosure by directly invoking a servlet.
CVE-2002-1742Arbitrary Perl functions can be loaded by calling a non-existent function that activates a handler.