CVE-2021-41086
📋 TL;DR
CVE-2021-41086 is a DOM-based cross-site scripting (XSS) vulnerability in jsuites JavaScript components. Attackers can inject malicious JavaScript by tricking users into copying and pasting content from a malicious source into the vulnerable HTML editor. This affects all users of jsuites versions before 4.9.11.
💻 Affected Systems
- jsuites
📦 What is this software?
Jsuites by Jsuites
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, session hijacking, credential theft, and unauthorized actions performed on behalf of the victim user.
Likely Case
Session hijacking, credential theft, and unauthorized data access through malicious JavaScript execution in the victim's browser context.
If Mitigated
Limited impact with proper content security policies, input validation, and user awareness training.
🎯 Exploit Status
Exploitation requires user interaction (copy-paste) but is straightforward once the user is tricked.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.9.11
Vendor Advisory: https://github.com/jsuites/jsuites/security/advisories/GHSA-qh7x-j4v8-qw5w
Restart Required: No
Instructions:
1. Update jsuites to version 4.9.11 or later. 2. Replace vulnerable jsuites files with patched versions. 3. Clear browser caches to ensure new versions are loaded.
🔧 Temporary Workarounds
Implement Content Security Policy
allAdd CSP headers to restrict script execution from untrusted sources
Content-Security-Policy: script-src 'self'
Disable Clipboard Paste
allTemporarily disable paste functionality in jsuites HTML editor
Set editor configuration to disable paste: { paste: false }
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all clipboard content
- Deploy web application firewall (WAF) rules to detect and block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Check if jsuites version is below 4.9.11 in your application dependencies or loaded scriptsCheck Version:
Check package.json for jsuites version or inspect loaded JavaScript filesVerify Fix Applied:
Confirm jsuites version is 4.9.11 or later and test that pasted content is properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript execution patterns
- Suspicious paste events in editor components
Network Indicators:
- Requests to external domains from editor context
- Unusual script loading patterns
SIEM Query:
search for 'innerHTML' modifications with external content or suspicious script tags in application logs🔗 References
- https://github.com/jsuites/jsuites/commit/d47a6f4e143188dde2742f4cffd313e1068ad3b3
- https://github.com/jsuites/jsuites/commit/fe1d3cc5e339f2f4da8ed1f9f42271fdf9cbd8d2
- https://github.com/jsuites/jsuites/security/advisories/GHSA-qh7x-j4v8-qw5w
- https://github.com/jsuites/jsuites/commit/d47a6f4e143188dde2742f4cffd313e1068ad3b3
- https://github.com/jsuites/jsuites/commit/fe1d3cc5e339f2f4da8ed1f9f42271fdf9cbd8d2
- https://github.com/jsuites/jsuites/security/advisories/GHSA-qh7x-j4v8-qw5w
