Unsanitized user input in raw HTML strings (XSS)

• Rule ID: php_lang_raw_html_using_user_input
• Languages: php
• Source: raw_html_using_user_input.yml

Description

Including unsanitized user input in HTML exposes your application to cross-site scripting (XSS) attacks. This vulnerability allows attackers to inject malicious scripts into web pages viewed by other users.

Remediations

• Do not include user input directly in HTML strings. This practice can lead to XSS vulnerabilities.

  $html = "<h1>{$_GET["title"]}</h1>"; // unsafe

• Do use a templating language like Twig, and keep the template in a separate file. Templating languages automatically handle input sanitization, reducing the risk of XSS.
• Do sanitize user input when HTML strings must be used, to prevent malicious code injection.

  $html = "<h1>${htmlspecialchars($_GET["title"])}</h1>";

References

• OWASP Cross-Site Scripting (XSS) Cheatsheet

Associated CWE

• CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

OWASP Top 10

• A03:2021 - Injection

Configuration

To skip this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --skip-rule=php_lang_raw_html_using_user_input

To run only this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --only-rule=php_lang_raw_html_using_user_input