CVE-2025-31687
📋 TL;DR
This vulnerability allows attackers to inject malicious scripts into web pages generated by Drupal sites using the SpamSpan filter module. When exploited, it enables cross-site scripting (XSS) attacks that can steal user sessions, deface websites, or redirect users to malicious sites. All Drupal sites using vulnerable versions of the SpamSpan filter module are affected.
💻 Affected Systems
- Drupal SpamSpan filter module
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, take full control of the Drupal site, install backdoors, or compromise user data through session hijacking.
Likely Case
Attackers inject malicious JavaScript to steal user session cookies, redirect users to phishing sites, or deface website content.
If Mitigated
With proper input validation and output encoding, the impact is limited to minor content manipulation that doesn't affect site functionality.
🎯 Exploit Status
XSS vulnerabilities typically have low exploitation complexity, requiring only crafted input to trigger.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.1
Vendor Advisory: https://www.drupal.org/sa-contrib-2025-016
Restart Required: No
Instructions:
1. Update the SpamSpan filter module to version 3.2.1 via Drupal's update manager or Composer. 2. Clear Drupal caches. 3. Verify the update was successful.
🔧 Temporary Workarounds
Disable SpamSpan filter module
linuxTemporarily disable the vulnerable module until patching is possible
drush pm-disable spamspan_filter
Implement Content Security Policy
allAdd CSP headers to mitigate XSS impact by restricting script execution
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads
- Enable Drupal's built-in XSS protection features and ensure input validation is enforced
🔍 How to Verify
Check if Vulnerable:
Check the SpamSpan filter module version in Drupal's Extend page or via 'drush pm-list | grep spamspan_filter'Check Version:
drush pm-list --fields=name,version --format=json | grep -A1 spamspan_filterVerify Fix Applied:
Confirm module version is 3.2.1 or higher and test input fields that use SpamSpan filtering📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests containing script tags or JavaScript code to form submissions
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests with encoded script payloads in parameters
- Outbound connections to suspicious domains following form submissions
SIEM Query:
web_access_logs WHERE url_parameters CONTAINS ANY('<script', 'javascript:', 'onerror=', 'onload=')