You are assisting in the development of a new accounts payable program for internal use within your company

You are assisting in the development of a new accounts payable program for internal use within your company. The major business stakeholder, the V.P. of Finance, wants to skip some of the security testing for the program to reduce costs. Her argument is that the program will be used internally, and rigorous testing is unnecessary. Based upon the course, what are your arguments against this approach?