Systems and methods for detecting and mitigating attacks that exploit vulnerabilities of a website are provided, according to various embodiments described below and herein. A computing device issues a request for a web page that is stored on a server. The server receives a request and issues a response that includes the requested web page and interceptor code injected into the response. The computing device receives the response, renders the web content and generates an interceptor from the interceptor code. The interceptor intercepts requests, responses to dynamically update the webpage and responses containing a challenge. When a computing device issues a request to the server to dynamically update the webpage, the server issues a response to the computing device that includes a challenge. Once computing device issues a request that includes an answer to the challenge, the server validates the answer and issues a response that dynamically updates the webpage.