Constructing secure web applications with proper data validations

With the advent of World Wide Web, information sharing through internet increased drastically. So web applications security is today's most significant battlefield between attackers and resources of web service. It is likely to remain so for the foreseeable future. By considering recent attacks it has been found that major attacks in Web Applications have been carried out even when system having most significant network level security. Poor input validation mechanisms that using in Web Applications shall causes to launching vulnerable web applications, which easy to exploit easy in future stages. Critical Web Application Vulnerabilities like Cross Site Scripting (XSS) and Injections (SQL, PHP, LDAP, SSL, XML, Command, and Code) are happen because of base level Validations, and it is enough to update system in unauthorized way or may be causes to exploit the system. In this paper we present those issues in data validations strategies, to avoid deployment of vulnerable web applications.