The mechanisms of attack or the affected technologies might be different, but the mistake is fundamentally the same. Template engines can be used on the server or client, so both 'sides' could be affected by injection. In some cases, XSS-style attacks can work, which can obscure the root cause if the developer does not closely investigate the root cause of the error.

The syntax varies depending on the language. For example, in some template languages, an attacker could inject the expression '' and determine if the output returns '49' instead. Make an index.pug file, and an index.html file in the root project directory. Step 2: Open the project folder code editor. g is for global install and it is optional. If an attacker can influence input into a template before it is processed, then the attacker can invoke arbitrary expressions, i.e. Project Setup: Step 1: Install pug by running the following command. Template engines often have their own custom command or expression language. Some CMS (Content Management Systems) also use templates. Such engines include Twig, Jinja2, Pug, Java Server Pages, FreeMarker, Velocity, ColdFusion, Smarty, and many others - including PHP itself. Many web applications use template engines that allow developers to insert externally-influenced values into free text or messages in order to generate a full web page, document, message, etc.

Pug template injection