Security is an integral part of most software systems but it is not considered as an explicit part in the development process yet. Input validation is the most critical part of software security that is not covered in the design phase of software development life-cycle resulting in many security vulnerabilities. Our objective is to extend UML to new integrated framework for model driven security engineering leading to ideal way to design more secure software. Input validation in UML has not been addressed previously, hence we incorporate input validation into UML diagrams such as use case, class, sequence and activity. This approach has some advantages such as preventing from common input tampering attacks, having both security and convenience in software at high level of abstraction and ability of solving the problem of weak security background for developers.