TLDR: Misconfigured Liquid, introduced in 2006 by Shopify, can result in security vulnerabilities such as code injection, cross-site scripting (XSS), and unintended exposure of sensitive data. These risks often arise from improper input handling, insecure template configurations, and failure to implement security controls, violating key OWASP Top Ten principles like Input Validation, Output Encoding, and Access Controls.
https://shopify.github.io/liquid/
Improper input validation in Liquid templates allows unsanitized user inputs to be rendered, increasing the risk of code injection or data tampering. This misstep violates the OWASP Top Ten's recommendation to validate all inputs to avoid such vulnerabilities.
https://owasp.org/www-community/Input_Validation
Developers often bypass Liquid’s built-in filters or apply inappropriate filters, which can expose the application to XSS. Using raw outputs without proper escaping or filtering allows attackers to inject malicious JavaScript or HTML, breaching the OWASP Top Ten's Output Encoding standards.
https://developer.mozilla.org/en-US/docs/Web/Security/Output_Encoding
Dynamic template inclusion in Liquid without validation can lead to unauthorized rendering of external or untrusted files. This underscores the need for strict Access Controls and allowlists, aligning with OWASP Top Ten principles for secure resource management.
https://shopify.github.io/liquid/tags/include/
Embedding sensitive variables or exposing configuration details directly in Liquid templates without encryption increases the risk of data leakage. Such practices contravene OWASP Top Ten recommendations on secure Data Encryption and sensitive data handling.
https://owasp.org/www-community/Data_Encryption
Inadequate Error Handling in Liquid templates may reveal sensitive information such as stack traces or debugging data to attackers. Proper masking of error outputs is essential to meet the OWASP Top Ten guidelines on secure Error Handling.
https://owasp.org/www-community/Error_Handling
Over-reliance on Liquid's Framework Defaults without customization for specific use cases can leave applications vulnerable. Reviewing and hardening these defaults is critical to reduce risks, as recommended by the OWASP Top Ten.
https://owasp.org/www-community/Framework_Security_Project
Integrating Liquid with API Endpoints without enforcing CORS or Cross-Domain Permissions can create security gaps. These configurations must align with OWASP Top Ten's Policy Enforcement best practices to prevent unauthorized access.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
Logging raw inputs or sensitive variables in Liquid templates without sanitization or encryption can increase exposure risks. Secure Logging practices, including limiting log access and masking sensitive data, are necessary to align with OWASP Top Ten guidelines.
https://owasp.org/www-community/Logging_and_Monitoring_Cheat_Sheet
Neglecting regular dependency checking for Liquid plugins or associated libraries can expose applications to vulnerabilities in outdated components. Utilizing alerts for vulnerable components and dependency management tools ensures compliance with OWASP Top Ten security principles.
https://owasp.org/www-project-dependency-check/
Lastly, remote code execution (RCE) risks can emerge in Liquid if untrusted inputs are rendered without sandboxing or filtering. Ensuring all inputs are validated and processed securely is essential, aligning with OWASP Top Ten's focus on secure template engine practices.