Misconfigured Handlebars.js, Misconfigured Mustache, Misconfigured Jinja2, Misconfigured EJS, Misconfigured Thymeleaf, Misconfigured Pug, Misconfigured Twig, Misconfigured Liquid, Misconfigured Smarty, Misconfigured Freemarker
TLDR: Misconfigured Template Engines can lead to severe security vulnerabilities by allowing unintended code execution, data leakage, or input injection. These risks often stem from failing to sanitize user inputs, bypassing Input Validation and Input Sanitization, both critical components of the OWASP Top Ten guidelines.
https://owasp.org/www-project-top-ten/
Improper handling of user inputs within Template Engines frequently results in Remote Code Execution (RCE). For example, an attacker may inject malicious payloads into templates if input validation is inadequate. This bypass of Sanitization Routines exposes systems to unauthorized actions, directly violating the OWASP Top Ten principle of securing Serialization Settings and Resource Access.
https://owasp.org/www-community/attacks/Template_Injection
Input Validation failures in Template Engines open doors for template injection attacks. Misconfigured engines may process malicious inputs as executable code, enabling attackers to manipulate sensitive data or execute harmful scripts. The OWASP Top Ten emphasizes robust validation mechanisms to mitigate these risks.
https://developer.mozilla.org/en-US/docs/Web/Security/Input_Validation
A frequent misstep is failing to configure strict Output Encoding policies within Template Engines. Attackers can exploit this oversight to inject malicious JavaScript or other client-side code, violating the OWASP Top Ten recommendations on Encoding and Escaping. Proper Output Encoding ensures that outputs are safely rendered.
https://owasp.org/www-community/Encoding_Escaping
Many Template Engines rely on default configurations that prioritize ease of use over security. These Framework Defaults often enable features that allow unvalidated input rendering, posing significant security risks. The OWASP Top Ten highlights the importance of reviewing and customizing default settings to meet application-specific security requirements.
https://www.owasp.org/index.php/Framework_Security_Project
Access Controls in Template Engines are critical yet often neglected. Misconfigurations may unintentionally expose sensitive templates or system-level commands to unauthorized users, leading to data breaches or privilege escalation. Proper Role-Based Access Control (RBAC) helps mitigate these threats.
https://developer.mozilla.org/en-US/docs/Web/Security/Access_Control
Another concern is inadequate handling of CORS in applications using Template Engines. If misconfigured, Cross-Domain Permissions can permit unauthorized embedding or sharing of template-rendered data, contrary to the OWASP Top Ten's principles on securing API Endpoints.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
Logging of Sensitive Data within Template Engines can introduce additional vulnerabilities if not properly sanitized. Logging raw user inputs or rendering sensitive variables without encryption increases exposure risks, conflicting with the OWASP Top Ten’s Data Encryption best practices.
https://owasp.org/www-community/Logging
Insecure implementations of Template Engines often overlook proper Error Handling practices. Detailed stack traces or raw error messages can provide attackers with insights into application architecture, enabling exploitation of known vulnerabilities. Error Handling should mask sensitive details to comply with the OWASP Top Ten.
https://owasp.org/www-community/Error_Handling
Lastly, developers need to continuously assess the security of their Template Engines through Dependency Checking and Alerts for Vulnerable Components. Many engines depend on external libraries that require regular updates. Package Management tools like NPM or Maven can automate this process and prevent exploitation of outdated components.
https://owasp.org/www-community/OWASP_Dependency_Check_Project