Alteryx Server HTML Injection Vulnerability in Pages Component

A HTML injection vulnerability has been identified in Alteryx Server version 2023.1.1.460. This issue allows users to inject arbitrary HTML into the pages component, which is then rendered in a trusted context. As a result, end users could be deceived into revealing sensitive information, such as login credentials, or inadvertently performing harmful actions. The vulnerability requires user interaction, making it particularly effective for phishing or social engineering attacks.

Impact

Exploitation of this vulnerability could lead to unauthorized actions being performed by users, such as disclosing sensitive information or being manipulated into taking certain actions. Additionally, if the injected HTML is exploited with other client-side vulnerabilities, it could result in stealing user session information or other confidential data.

Reproduction

To reproduce this vulnerability, a user must have permission to edit pages within Alteryx Server. Once in the text editor, which has limited styling options, the user can inject HTML, such as a web form, into the page. After saving the changes, the injected HTML will be rendered, creating a form that prompts users to enter sensitive information, like usernames and passwords. This form can be directed to an external server, potentially harvesting the entered data.

Remediation

To address this vulnerability, Alteryx Server should implement input validation and sanitization for user-generated content, particularly on editable pages. Employing an HTML whitelist to allow only certain tags and attributes can help mitigate risks. Additionally, ensuring that user input is properly encoded before being displayed can prevent malicious HTML from being executed. Integrating a secure WYSIWYG editor that automatically sanitizes content before it's saved can also be an effective measure.