CVE-2021-47817
📋 TL;DR
OpenEMR 5.0.2.1 contains a stored cross-site scripting vulnerability in user profile parameters that allows authenticated attackers to inject malicious JavaScript. This can lead to remote command execution through web shell download and execution. Only authenticated users can exploit this vulnerability.
💻 Affected Systems
- OpenEMR
📦 What is this software?
Openemr by Open Emr
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining remote command execution, data exfiltration, and persistent access through web shells.
Likely Case
Unauthorized data access, session hijacking, and limited command execution within the OpenEMR application context.
If Mitigated
Limited impact with proper input validation and output encoding preventing JavaScript execution.
🎯 Exploit Status
Exploit requires authenticated access but payload execution is straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.0.2.2 and later
Vendor Advisory: https://www.open-emr.org/
Restart Required: No
Instructions:
1. Download latest OpenEMR version from official site. 2. Backup current installation. 3. Replace vulnerable files with patched version. 4. Verify functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for user profile parameters to filter JavaScript and special characters.
Modify user profile handling code to sanitize inputs before processing
🧯 If You Can't Patch
- Implement web application firewall with XSS protection rules
- Restrict user profile modification permissions to trusted administrators only
🔍 How to Verify
Check if Vulnerable:
Check OpenEMR version in admin interface or via version.php file.Check Version:
grep -r '\$openemr_version' /path/to/openemr/interface/globals.phpVerify Fix Applied:
Test user profile parameter injection with test payloads after patching.📡 Detection & Monitoring
Log Indicators:
- Unusual user profile modifications
- JavaScript payloads in POST requests to user profile endpoints
Network Indicators:
- HTTP requests with JavaScript in user profile parameters
- Unexpected outbound connections after profile updates
SIEM Query:
source="web_logs" AND (uri_path="/interface/usergroup/user_info.php" OR uri_path="/interface/usergroup/user_settings.php") AND (http_method="POST" OR http_method="PUT") AND (request_body CONTAINS "<script>" OR request_body CONTAINS "javascript:")🔗 References
- https://blog.sonarsource.com/openemr-5-0-2-1-command-injection-vulnerability?utm_medium=cpc&utm_source=twitter&utm_campaign=openemr&utm_term=security&utm_content=tofu
- https://sourceforge.net/projects/openemr/files/OpenEMR%20Current/5.0.2.1/openemr-5.0.2.tar.gz/download
- https://www.exploit-db.com/exploits/49784
- https://www.open-emr.org/
- https://www.vulncheck.com/advisories/openemr-remote-code-execution
- https://www.youtube.com/watch?v=H8VWNwWgYJo&feature=emb_logo
