Attack Surface: Cross-Site Scripting (XSS) via Data Injection
Description: Attackers inject malicious JavaScript code into the chart data, which is then executed in the context of the victim's browser when the chart is rendered.
* How Chartkick Contributes: Chartkick acts as a conduit, passing unsanitized data directly to the underlying JavaScript charting libraries. It's the mechanism by which the malicious data reaches the vulnerable rendering engine.
* Example: An attacker enters <script>alert('XSS')</script> as a product name, which is then displayed as a label in a chart. When the chart renders, the script executes.
* Impact: Compromise of user accounts, session hijacking, defacement of the website, redirection to malicious sites, theft of cookies, and other client-side attacks.
* Risk Severity: Critical
* Mitigation Strategies:
* Input Validation and Sanitization: Always rigorously validate and sanitize all user-supplied data before passing it to chartkick. Use framework-provided sanitization helpers (e.g., sanitize, h in Rails) or dedicated HTML sanitization libraries. Ensure sanitization is context-aware.
* Output Encoding: Ensure that data is properly encoded when it's rendered in the HTML.
* Content Security Policy (CSP): Implement a strict CSP to restrict the sources from which scripts can be loaded.
Attack Surface: Cross-Site Scripting (XSS) via Chart Options Injection
Description: Attackers inject malicious code into chart options (e.g., title, subtitle, custom JavaScript callbacks).
* How Chartkick Contributes: Chartkick passes these options directly to the underlying charting library without sanitization. It's the direct pathway for the malicious code to reach the rendering engine.
* Example: An attacker provides a chart title like <img src=x onerror=alert('XSS')>, which is then used in the title option.
* Impact: Same as XSS via data injection: account compromise, session hijacking, etc.
* Risk Severity: High
* Mitigation Strategies:
* Sanitize Options: Apply the same rigorous sanitization and escaping to user-supplied data used in chart options as for chart data.
* Avoid User Input in Callbacks: Minimize/avoid using user input directly within JavaScript callbacks in chart options. If unavoidable, treat this input as extremely high-risk and sanitize meticulously.
* CSP: A strong CSP also mitigates this risk.
Attack Surface: Exploitation of Underlying Charting Library Vulnerabilities
Description: Vulnerabilities in the JavaScript charting libraries (Chart.js, Google Charts, Highcharts) that chartkick uses can be exploited.
* How Chartkick Contributes: Chartkick's direct dependency on these external libraries makes their vulnerabilities a direct part of chartkick's attack surface. Chartkick is the component that loads and utilizes these potentially vulnerable libraries.
* Example: A known XSS vulnerability in an older version of Chart.js is exploited through chartkick, even if the application sanitizes its own data.
* Impact: Varies, but can include XSS, data breaches, or DoS, depending on the underlying library vulnerability.
* Risk Severity: High (Potentially Critical, depending on the underlying library vulnerability)
* Mitigation Strategies:
* Keep Libraries Updated: Regularly update chartkick and the underlying JavaScript charting libraries. Use dependency management tools. Monitor security advisories.
* Subresource Integrity (SRI): Use SRI tags when including the JavaScript charting libraries.
* Content Security Policy (CSP): A strong CSP can limit the impact of vulnerabilities.
* Vulnerability Scanning: Regularly scan your application and its dependencies.