CVE-2025-13979: Drupal Mini Site Stored XSS Vulnerability

CVE-2025-13979 Overview

CVE-2025-13979 is a Privilege Defined With Unsafe Actions vulnerability in the Drupal Mini site module that enables Stored Cross-Site Scripting (XSS) attacks. This security flaw allows authenticated attackers with certain privileges to inject malicious scripts that persist within the application and execute when other users access affected pages.

Critical Impact

Authenticated attackers can exploit unsafe privilege definitions to inject persistent malicious scripts, potentially compromising user sessions, stealing credentials, or performing unauthorized actions on behalf of other users.

Affected Products

• Drupal Mini site module versions from 0.0.0 before 3.0.2

Discovery Timeline

• 2026-01-28 - CVE CVE-2025-13979 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2025-13979

Vulnerability Analysis

This vulnerability stems from CWE-267 (Privilege Defined With Unsafe Actions), where the Mini site module grants privileges that include inherently dangerous capabilities. The unsafe privilege configuration allows authenticated users to store malicious content that is not properly sanitized before being rendered to other users.

When exploited, the Stored XSS attack persists within the Drupal application's data store. Unlike reflected XSS attacks that require victim interaction with a malicious link, stored XSS payloads execute automatically when victims simply navigate to the affected page, making this attack vector particularly dangerous for multi-user environments.

Root Cause

The root cause lies in the privilege definition within the Drupal Mini site module. The module defines user privileges that inadvertently allow unsafe actions, specifically the ability to store user-controlled content without adequate input sanitization or output encoding. This design flaw enables authenticated users with these elevated privileges to bypass security controls intended to prevent script injection.

Attack Vector

The attack is network-based and requires low-privilege authentication to exploit. An attacker must first authenticate to the Drupal application with access to the Mini site module functionality. Once authenticated, the attacker can inject malicious JavaScript or HTML content through vulnerable input fields. This content is stored server-side and rendered without proper encoding when other users access the affected mini site pages.

The stored payload executes in the browser context of any user viewing the compromised content, enabling session hijacking, credential theft, defacement, or further attack propagation. The lack of user interaction required for payload execution (beyond normal site navigation) significantly increases the exploitability of this vulnerability.

Detection Methods for CVE-2025-13979

Indicators of Compromise

• Unexpected JavaScript code or HTML tags in Mini site content fields or database entries
• Unusual user session activity or authentication anomalies following Mini site page visits
• Browser developer console errors indicating blocked or executed inline scripts
• Reports from users experiencing unexpected redirects, pop-ups, or credential prompts

Detection Strategies

• Implement web application firewall (WAF) rules to detect common XSS payloads in request parameters
• Enable Content Security Policy (CSP) headers to block unauthorized inline script execution
• Monitor Drupal watchdog logs for suspicious content modifications in Mini site entities
• Deploy endpoint detection and response (EDR) solutions to identify browser-based attack indicators

Monitoring Recommendations

• Review Mini site content submissions for suspicious patterns such as <script> tags, event handlers, or encoded payloads
• Monitor user privilege assignments within the Mini site module for unauthorized escalation
• Implement real-time alerting for CSP violation reports indicating potential XSS attempts
• Audit authentication logs for anomalous session activity following exposure to Mini site pages

How to Mitigate CVE-2025-13979

Immediate Actions Required

• Update the Drupal Mini site module to version 3.0.2 or later immediately
• Review and audit existing Mini site content for malicious scripts or suspicious HTML
• Restrict Mini site module permissions to trusted administrative users only
• Implement Content Security Policy headers to mitigate XSS impact while patching

Patch Information

The Drupal security team has released version 3.0.2 of the Mini site module to address this vulnerability. Administrators should update through Drupal's standard module update process. For detailed patch information and upgrade instructions, refer to the Drupal Security Advisory.

Workarounds

• Disable the Mini site module entirely if not critical to site operations until patching is complete
• Implement strict Content Security Policy headers with script-src 'self' to block inline script execution
• Review and remove unnecessary user privileges associated with Mini site content creation
• Deploy a web application firewall with XSS detection rules as a compensating control

# Example CSP header configuration for Apache
# Add to .htaccess or VirtualHost configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self'"