Retool Self-Hosted XSS Scanner

Retool Self-Hosted is used by developers and companies to build and manage internal tools by connecting data sources and APIs. It offers a customizable interface that empowers users to create and manipulate applications visually. The platform is typically used in businesses where custom software solutions are required to streamline internal processes. By integrating various data-handling components, Retool improves efficiency and productivity. The self-hosted version allows organizations to run Retool within their own infrastructure, offering enhanced control over data and privacy. Users can utilize Retool to perform data operations, generate reports, and automate workflows.

Cross-Site Scripting (XSS) is a vulnerability that enables attackers to inject arbitrary JavaScript into a target domain. In Retool Self-Hosted, this vulnerability exists within the custom component collections iframe handler, where the postMessage event listener accepts messages from any origin without validation. Attackers can exploit this flaw to execute malicious scripts in the context of the user's session. XSS vulnerabilities can be used to steal authentication cookies, perform actions on behalf of the user, and redirect users to malicious websites. Protecting applications from XSS is crucial to maintaining user trust and data integrity.

The vulnerability occurs due to improper validation of the origin in the postMessage event listener of the custom-component-collections.html file. This endpoint lacks an origin check, allowing any source to send a message that includes JavaScript code via data URLs. The dynamically imported scripts can execute within the application's origin, leading to potential security violations. Attackers can particularly leverage this to manipulate the Retool instance, altering its intended functionality. Given the high risk associated with arbitrary script execution, immediate attention to this vulnerability is imperative.

When exploited, this XSS vulnerability could lead to unauthorized actions within the Retool application, compromising user data and application integrity. Malicious users may execute scripts that lead to data theft, unauthorized transactions, or even complete control over the affected instance. Enterprises could face significant reputational damage and loss of confidential information. Additionally, such vulnerabilities might open pathways for further attacks, posing a substantial threat to organizational security.

REFERENCES

• https://docs.retool.com/releases
• https://docs.retool.com/changelog/disclosures/custom-component-xss