Design/Logic Flaw

An arbitrary file upload vulnerability in the file upload module of express-fileupload 1.3.1 allows attackers to execute arbitrary code via a crafted PHP file. NOTE: the vendor’s position is that the observed behavior can only occur with “intentional misusing of the API”: the express-fileupload middleware is not responsible for an application’s business logic (e.g., determining whether or how a file should be renamed).