CVE-2021-47718
📋 TL;DR
OpenBMCS 2.4 contains an unauthenticated directory listing vulnerability that allows attackers to browse sensitive directories and access configuration files, database credentials, and system information. This affects all systems running OpenBMCS 2.4 with default configurations. The vulnerability enables information disclosure without requiring authentication.
💻 Affected Systems
- OpenBMCS
📦 What is this software?
Openbmcs by Openbmcs
⚠️ Risk & Real-World Impact
Worst Case
Attackers obtain database credentials and configuration files, leading to full system compromise, data exfiltration, or lateral movement within the network.
Likely Case
Attackers discover sensitive system information and configuration details that can be used for further attacks or reconnaissance.
If Mitigated
Limited exposure with only non-sensitive directory contents accessible, though still revealing system structure.
🎯 Exploit Status
Exploitation requires only web browser access to vulnerable directories. Public exploit code is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.openbmcs.com
Restart Required: No
Instructions:
1. Check OpenBMCS website for security updates
2. Upgrade to a patched version if available
3. Apply workarounds if patch is not available
🔧 Temporary Workarounds
Disable Directory Listing
allConfigure web server to disable directory listing for sensitive paths
# For Apache: Add 'Options -Indexes' to .htaccess or virtual host config
# For Nginx: Add 'autoindex off;' to server block
Restrict Access to Sensitive Directories
allImplement access controls to block unauthenticated access to /debug/ and /php/ directories
# Apache example: <Directory /path/to/debug>
Require all denied
</Directory>
🧯 If You Can't Patch
- Implement network segmentation to isolate OpenBMCS systems from critical assets
- Deploy web application firewall (WAF) rules to block directory traversal attempts
🔍 How to Verify
Check if Vulnerable:
Access http://[openbmcs-host]/debug/ or http://[openbmcs-host]/php/ in a web browser. If directory contents are visible, the system is vulnerable.Check Version:
Check OpenBMCS web interface or configuration files for version informationVerify Fix Applied:
Attempt to access the same URLs after applying fixes. You should receive '403 Forbidden' or similar error instead of directory listing.📡 Detection & Monitoring
Log Indicators:
- Multiple 200 OK responses to directory paths like /debug/, /php/
- Unusual access patterns to sensitive directories
Network Indicators:
- HTTP GET requests to /debug/ and /php/ directories from untrusted sources
SIEM Query:
source="web_server_logs" AND (uri_path="/debug/" OR uri_path="/php/") AND status=200