What would most likely lead to a CGI (Common Gateway Interface) security problem?

External data supplied by the user. -common gateway interface is an older form of scripting that was used extensively in early web systems. cgi scripts could be used to capture data from a user using simple forms. the cgi script ran on the web server, and it interacted with the client browser. cgi is frowned upon in new applications because of its security issues, but it still widely used in older systems. although the answer is not given in the paragraph from the book, the answer would be d. reference: mike pastore and emmett dulaney, security+ study guide, 2nd edition, alameda, sybex, 2004, p 136