CVE-2024-53989
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in rails-html-sanitizer 1.6.0 when used with Rails >=7.1.0. Attackers can inject malicious content if HTML5 sanitization is enabled and developers have overridden allowed tags for the 'noscript' element. Applications using these specific configurations are affected.
💻 Affected Systems
- rails-html-sanitizer
- Ruby on Rails
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Successful exploitation could allow attackers to execute arbitrary JavaScript in victims' browsers, potentially stealing session cookies, performing actions as the user, or defacing the application.
Likely Case
Attackers inject malicious scripts that execute in users' browsers, leading to session hijacking, credential theft, or unauthorized actions within the application.
If Mitigated
With proper input validation and output encoding, the impact is limited to potential minor data exposure or UI manipulation.
🎯 Exploit Status
Exploitation requires specific configuration conditions and user interaction with malicious content.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.6.1
Vendor Advisory: https://github.com/rails/rails-html-sanitizer/security/advisories/GHSA-rxv5-gxqc-xx8g
Restart Required: Yes
Instructions:
1. Update Gemfile to specify 'rails-html-sanitizer', '>= 1.6.1'. 2. Run 'bundle update rails-html-sanitizer'. 3. Restart your Rails application server.
🔧 Temporary Workarounds
Disable HTML5 sanitization
allTemporarily disable HTML5 sanitization feature if not required
config.action_view.sanitizer_vendor = Rails::HTML4::Sanitizer
Remove noscript tag overrides
allRemove any custom configurations that override allowed tags for 'noscript' element
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to mitigate XSS impact
- Add additional input validation and output encoding layers for user-supplied HTML
🔍 How to Verify
Check if Vulnerable:
Check Gemfile.lock for 'rails-html-sanitizer (1.6.0)' and ensure Rails version is >=7.1.0Check Version:
bundle show rails-html-sanitizerVerify Fix Applied:
Verify Gemfile.lock shows 'rails-html-sanitizer (1.6.1)' or higher📡 Detection & Monitoring
Log Indicators:
- Unusual HTML content containing noscript tags
- Multiple failed sanitization attempts
Network Indicators:
- Suspicious JavaScript payloads in HTTP requests
- Unexpected script execution in browser responses
SIEM Query:
source="rails_app" AND (message="*noscript*" OR message="*sanitization*error*")