CVE-2024-55888
📋 TL;DR
Hush Line whistleblower management systems running versions 0.1.0 through 0.3.4 lack Content Security Policy and security headers, allowing attackers to bypass cross-site scripting filters. This affects all deployments using vulnerable versions of the open-source software. Attackers could inject malicious scripts that execute in users' browsers.
💻 Affected Systems
- Hush Line
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of whistleblower submissions, data theft, session hijacking, and malware distribution to users accessing the platform.
Likely Case
Stealing whistleblower submissions, session cookies, and injecting malicious content into the platform.
If Mitigated
Limited impact with proper network segmentation, but still potential for data leakage from the application.
🎯 Exploit Status
XSS exploitation is well-understood and tools exist, but no specific exploit for this CVE is publicly documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.3.5
Vendor Advisory: https://github.com/scidsg/hushline/security/advisories/GHSA-m592-g8qv-hrqx
Restart Required: Yes
Instructions:
1. Backup your current Hush Line installation. 2. Update to version 0.3.5 or later using your package manager or by downloading from GitHub. 3. Restart the Hush Line service. 4. Verify the fix by checking security headers in browser developer tools.
🔧 Temporary Workarounds
Add Security Headers via Reverse Proxy
linuxConfigure nginx or Apache to add Content-Security-Policy and other security headers
# For nginx: add to server block
add_header Content-Security-Policy "default-src 'self'; script-src 'self';" always;
# For Apache: add to .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self';"
# Additional headers to add:
# X-Content-Type-Options: nosniff
# X-Frame-Options: DENY
# Referrer-Policy: strict-origin-when-cross-origin
🧯 If You Can't Patch
- Isolate the Hush Line instance behind a WAF with XSS protection rules
- Implement network segmentation to limit access to only authorized users
🔍 How to Verify
Check if Vulnerable:
Check if Content-Security-Policy header is present in HTTP responses using browser developer tools or curl: curl -I https://your-hushline-instance.comCheck Version:
Check the Hush Line admin interface or run: grep -r "version" /path/to/hushline/ | grep -i "0\."Verify Fix Applied:
Verify version is 0.3.5+ and Content-Security-Policy header appears in HTTP responses📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests with script tags or JavaScript in parameters
- Multiple failed attempts to access admin endpoints
Network Indicators:
- HTTP requests containing <script> tags or JavaScript in query parameters
- Unusual outbound connections from the Hush Line server
SIEM Query:
source="web_server_logs" AND ("<script>" OR "javascript:" OR "onload=" OR "onerror=") AND dest_port=443