Editing Code injection (section)

=== Server Side Template Injection ===
[[Web template system|Template engines]] are often used in modern [[web application]]s to display dynamic data. However, trusting non-validated user data can frequently lead to critical vulnerabilities<ref>{{Cite web |date=2015-08-05 |title=Server-Side Template Injection |url=https://portswigger.net/research/server-side-template-injection |access-date=2022-05-22 |website=PortSwigger Research |archive-date=22 May 2022 |archive-url=https://web.archive.org/web/20220522214453/https://portswigger.net/research/server-side-template-injection |url-status=live }}</ref> such as server-side Side Template Injections. While this vulnerability is similar to [[cross-site scripting]], template injection can be leveraged to execute code on the web server rather than in a visitor's browser. It abuses a common workflow of web applications, which often use user inputs and templates to render a web page. The example below shows the concept. Here the template <code><nowiki>{{visitor_name}}</nowiki></code> is replaced with data during the rendering process.<syntaxhighlight lang="html">
Hello {{visitor_name}}

</syntaxhighlight>An attacker can use this workflow to inject code into the rendering pipeline by providing a malicious <code>visitor_name</code>. Depending on the implementation of the web application, he could choose to inject <code><nowiki>{{7*'7'}}</nowiki></code> which the renderer could resolve to <code>Hello 7777777</code>. Note that the actual web server has evaluated the malicious code and therefore could be vulnerable to [[remote code execution]].