The API in the WebKit Plug-ins component in Apple Safari before 9 does not provide notification of an HTTP Redirection (aka 3xx) status code to a plugin, which allows remote attackers to bypass intended request restrictions via a crafted web site.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.