CVE-2023-49657: Apache Superset XSS Vulnerability

CVE-2023-49657 Overview

A stored cross-site scripting (XSS) vulnerability has been identified in Apache Superset, the popular open-source data visualization and business intelligence platform. This vulnerability allows authenticated attackers with create/update permissions on charts or dashboards to inject malicious scripts or HTML snippets that persist within the application. When other users access the affected charts or dashboards, the stored malicious content executes in their browser context, potentially leading to session hijacking, credential theft, or further attacks against the Superset deployment.

Critical Impact

Authenticated attackers can store malicious scripts in Apache Superset charts and dashboards, enabling persistent XSS attacks against other users who view the compromised content.

Affected Products

• Apache Superset versions prior to 3.0.3
• Apache Superset 2.X versions (require configuration mitigation)
• All Apache Superset installations without proper Content Security Policy (CSP) configurations

Discovery Timeline

• 2024-01-23 - CVE-2023-49657 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-49657

Vulnerability Analysis

This stored XSS vulnerability (CWE-79) resides in Apache Superset's chart and dashboard functionality. The application fails to properly sanitize user-supplied input when authenticated users with create or update permissions modify chart configurations or dashboard elements. This improper input validation allows attackers to embed malicious JavaScript code or crafted HTML snippets that persist in the database and execute whenever the affected content is rendered for any user viewing the compromised charts or dashboards.

The attack requires low privileges (authenticated user with content creation rights) and network access to the Superset instance. However, successful exploitation can change scope by affecting other users who interact with the malicious content, potentially including administrators with elevated privileges.

Root Cause

The root cause of CVE-2023-49657 stems from insufficient input sanitization and the lack of proper Content Security Policy (CSP) enforcement in Apache Superset versions prior to 3.0.3. The application does not adequately validate or encode user-supplied content when storing chart configurations and dashboard elements, allowing script tags and event handlers to be preserved and later rendered without proper escaping.

Attack Vector

The attack follows a network-based vector where an authenticated attacker leverages their create/update permissions to inject malicious payloads into chart or dashboard objects. The attack requires user interaction—another user must view the compromised content for the payload to execute. Due to the stored nature of this XSS vulnerability, the malicious content persists across sessions and can impact multiple victims over time.

The attacker could craft payloads designed to steal session cookies, capture keystrokes, redirect users to phishing pages, or perform actions on behalf of the victim within the Superset application. If an administrator views the compromised content, the attacker could potentially escalate privileges or exfiltrate sensitive data accessible through the administrative interface.

Detection Methods for CVE-2023-49657

Indicators of Compromise

• Unusual JavaScript or HTML content present in chart configurations or dashboard definitions stored in the Superset database
• Unexpected outbound network requests from user browsers when viewing Superset dashboards
• Reports from users about unexpected behavior, pop-ups, or redirects when accessing specific charts or dashboards
• Audit logs showing suspicious create/update operations on charts or dashboards from specific user accounts

Detection Strategies

• Implement database monitoring to detect insertion of script tags, event handlers (like onerror, onload, onclick), or javascript: URIs in chart and dashboard content
• Deploy web application firewalls (WAF) with XSS detection signatures to monitor for malicious payloads in HTTP requests to Superset
• Enable Content Security Policy (CSP) violation reporting to capture and alert on blocked script execution attempts
• Review Superset audit logs for unusual patterns in chart/dashboard modifications by users

Monitoring Recommendations

• Configure CSP reporting endpoints and regularly analyze violation reports for potential XSS attack attempts
• Implement browser-based security monitoring to detect suspicious script execution patterns
• Monitor for abnormal network traffic originating from Superset user sessions
• Establish baseline behavior for chart/dashboard modifications and alert on anomalies

How to Mitigate CVE-2023-49657

Immediate Actions Required

• Upgrade Apache Superset to version 3.0.3 or later, which addresses this stored XSS vulnerability
• For Apache Superset 2.X installations that cannot be immediately upgraded, apply the Content Security Policy configuration mitigation
• Audit existing charts and dashboards for potentially malicious content
• Review user permissions to ensure the principle of least privilege is applied to create/update capabilities

Patch Information

Apache has addressed this vulnerability in Superset version 3.0.3. Organizations should upgrade to this version or later to receive the security fix. For detailed information about the patch and additional guidance, refer to the Apache Mailing List Discussion.

For Superset 2.X versions where immediate upgrade is not feasible, Apache provides a configuration-based mitigation using Talisman Content Security Policy settings.

Workarounds

• Apply the Talisman CSP configuration provided by Apache for 2.X versions (see configuration example below)
• Restrict chart and dashboard create/update permissions to only trusted users
• Enable strict output encoding on the web server/reverse proxy level
• Consider implementing additional WAF rules to filter XSS payloads

# Configuration for Apache Superset 2.X versions
# Add to superset_config.py

TALISMAN_CONFIG = {
    "content_security_policy": {
        "base-uri": ["'self'"],
        "default-src": ["'self'"],
        "img-src": ["'self'", "blob:", "data:"],
        "worker-src": ["'self'", "blob:"],
        "connect-src": [
            "'self'",
            "https://api.mapbox.com",
            "https://events.mapbox.com",
        ],
        "object-src": "'none'",
        "style-src": [
            "'self'",
            "'unsafe-inline'",
        ],
        "script-src": ["'self'", "'strict-dynamic'"],
    },
    "content_security_policy_nonce_in": ["script-src"],
    "force_https": False,
    "session_cookie_secure": False,
}