Specific functions exist for evaluating as well as executing during runtime, they are present in a whole host of programming languages.
These functions are useful in that they offer a high degree of flexibility to applications while also being powerful functions themselves which serve to empower the application.
However, as a consequence they also result in security vulnerabilities.
BadVal.js is our new JavaScript challenge built with this in mind.
This challenge will have you delve into stratagem that considers mitigation of risk as well as avoiding these functions in order to effectively secure your application.
Go try it out now 
BadVal.js