Abstract
Web applications (WAs) are constantly evolving and deployed at broad scale. However, they are exposed to a variety of attacks. The biggest challenge facing organizations is how to develop a WA that fulfills their requirements with respect to sensitive data exchange, E-commerce, and secure workflows. This paper identifies the most critical web vulnerabilities according to OWASP Top Ten, their corresponding attacks, and their countermeasures. The application of these countermeasures will guarantee the protection of the WAs against the most severe attacks and prevent several unknown exploits.