CVE-2025-3057: Drupal Core XSS Vulnerability

CVE-2025-3057 Overview

CVE-2025-3057 is a Cross-Site Scripting (XSS) vulnerability affecting Drupal core, one of the most widely deployed open-source content management systems. The vulnerability stems from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that execute in the context of authenticated users' browsers.

This XSS vulnerability in Drupal core enables attackers to potentially steal session cookies, perform unauthorized actions on behalf of users, redirect users to malicious sites, or deface web content. Given Drupal's extensive use in enterprise, government, and educational institutions, this vulnerability presents a significant risk to organizations relying on affected versions.

Critical Impact

Attackers can execute arbitrary JavaScript in victims' browsers, potentially leading to session hijacking, credential theft, and unauthorized actions within Drupal-powered websites.

Affected Products

• Drupal core versions 8.0.0 through 10.3.12
• Drupal core versions 10.4.0 through 10.4.2
• Drupal core versions 11.0.0 through 11.0.11
• Drupal core versions 11.1.0 through 11.1.2

Discovery Timeline

• 2025-03-31 - CVE-2025-3057 published to NVD
• 2025-04-15 - Last updated in NVD database

Technical Details for CVE-2025-3057

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The flaw exists within Drupal core's handling of user-supplied input, where insufficient sanitization allows malicious scripts to be embedded within web pages and subsequently executed in visitors' browsers.

The attack requires user interaction—specifically, a victim must navigate to a page containing the injected payload. Once triggered, the malicious script executes with the same privileges as the victim's session, enabling a range of attacks from cookie theft to complete account takeover. The vulnerability affects a wide range of Drupal versions spanning major releases 8.x, 10.x, and 11.x, indicating a long-standing issue in the core input handling mechanisms.

Root Cause

The root cause of CVE-2025-3057 lies in inadequate input validation and output encoding within Drupal core's web page generation routines. When user-controlled data is incorporated into HTML output without proper sanitization or contextual escaping, it creates an injection point where attackers can insert executable script content.

Drupal typically employs robust filtering mechanisms through its Twig templating engine and various sanitization APIs, but this vulnerability represents a gap where certain input paths bypass these protections. The changed scope (S:C in the CVSS vector) indicates that the vulnerability can affect resources beyond the vulnerable component itself, amplifying its potential impact.

Attack Vector

The attack vector for CVE-2025-3057 is network-based, requiring no privileges to exploit but necessitating user interaction. An attacker could craft a malicious URL or embed payload-containing content within the application. When an authenticated user with elevated privileges (such as an administrator) views the affected page, the injected script executes within their browser session.

Common exploitation scenarios include:

• Crafting malicious links distributed via email, social media, or other channels (Reflected XSS)
• Storing malicious content within the application that executes when other users view it (Stored XSS)
• Stealing session tokens or authentication cookies
• Performing actions on behalf of the victim user
• Modifying page content to phish for credentials

The vulnerability mechanism involves insufficient HTML entity encoding or JavaScript escaping when rendering user-supplied content. For detailed technical information about the specific affected functions and remediation details, refer to the Drupal Security Advisory SA-CORE-2025-001.

Detection Methods for CVE-2025-3057

Indicators of Compromise

• Unusual JavaScript execution patterns in browser developer tools or web application firewall logs
• Unexpected outbound requests to external domains from client browsers viewing Drupal pages
• Suspicious URL parameters containing encoded script tags or JavaScript event handlers
• Anomalous user session behavior indicating potential session hijacking

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common XSS payloads in request parameters and body content
• Implement Content Security Policy (CSP) headers with strict directives to prevent inline script execution and report violations
• Monitor server logs for requests containing suspicious patterns such as <script>, javascript:, onerror=, or encoded variants
• Utilize browser security headers like X-XSS-Protection and X-Content-Type-Options for additional defense layers

Monitoring Recommendations

• Enable detailed access logging and analyze patterns for requests containing potential XSS payloads
• Configure alerting on CSP violation reports to detect attempted XSS attacks in real-time
• Monitor for unusual JavaScript errors or resource loading patterns in client-side monitoring tools
• Implement user behavior analytics to detect account activity anomalies that may indicate session compromise

How to Mitigate CVE-2025-3057

Immediate Actions Required

• Update Drupal core to patched versions: 10.3.13, 10.4.3, 11.0.12, or 11.1.3 depending on your current major version
• Review and audit any custom modules or themes for similar input handling vulnerabilities
• Implement Content Security Policy headers to mitigate the impact of any XSS vulnerabilities
• Verify that all user sessions have been regenerated after patching to prevent exploitation of any previously compromised sessions

Patch Information

Drupal has released security updates addressing this vulnerability. Organizations should update to the following patched versions based on their current Drupal installation:

Detailed patch information and release notes are available in the Drupal Security Advisory SA-CORE-2025-001.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules specifically designed to block XSS payloads targeting Drupal installations
• Implement strict Content Security Policy headers to prevent execution of inline scripts and restrict script sources
• Limit administrative access to trusted IP ranges to reduce the attack surface for privilege escalation scenarios
• Enable browser-side XSS protections through security headers while planning the upgrade path

# Example: Add security headers to Apache configuration
# Add to .htaccess or Apache virtual host configuration

Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self'"
Header set X-Content-Type-Options "nosniff"
Header set X-Frame-Options "SAMEORIGIN"
Header set X-XSS-Protection "1; mode=block"