Abstract: A method by a service worker firewall middleware component is disclosed. The method includes causing a service worker firewall associated with a web site to be installed on a web browser, obtaining one or more rules in response to receiving a request from the service worker firewall for rules to be applied by the service worker firewall, sending a response to the service worker firewall, wherein the response includes the one or more rules, a digital signature for the one or more rules, and an indication of when the digital signature expires, wherein the digital signature is generated using a private key associated with the website, and receiving a rules violation report from the service worker firewall, wherein the rules violation report was generated as a result of the service worker firewall applying the one or more rules to cross-origin requests.

Abstract: A method by a web application layer proxy communicatively coupled between a web application client and a web application server for injecting content into a web page provided by the web application server. The method includes intercepting the web page, inserting scripting language code into the web page that allows the web application client to process web application layer responses to be sent by the web application layer proxy to the web application client, sending the web page with the scripting language code inserted to the web application client, and responsive to receiving a web application layer request from the web application client, generating and sending, without involvement of the web application server, a web application layer response to the web application client that is to be processed by the web application client using the inserted scripting language code.