Web applications and APIs have become more popular every year, and security risks haveincreased. Along with more security risks and the large amount of sensitive informationshared on web applications today, the problem grows. I therefore wanted to explore morein security deficiencies to increase my own knowledge and others in the field. To do that,a web application was developed and a survey was made of what security threats existtoday and what solutions they have. Some of the solutions encountered during theinvestigation were then implemented and tested in the web application. The result showedsome general solutions such as validation, which was a solution to a number of threats.The investigation also showed that security is not black and white and that it is possibleto implement actions but attackers can still find ways to attack systems.