^{CVE-2020-36243:}Command Injection Vulnerability in OpenEMR 5.0.2.1 Patient Portal

Overview

The vulnerability affects OpenEMR version 5.0.2.1, a widely used open-source electronic health records and medical practice management solution. The command injection flaw exists in the backup functionality accessible through the Patient Portal interface. When an authenticated user sends a specially crafted POST request to the /interface/main/backup.php endpoint, they can inject shell metacharacters that will be executed by the underlying operating system with the permissions of the web server user. This vulnerability is particularly severe as it could allow attackers to gain unauthorized access to patient health records, modify medical data, or potentially compromise the entire server hosting the OpenEMR installation.

Remediation

Users of OpenEMR 5.0.2.1 should immediately upgrade to OpenEMR 5.0.2 Patch 5 or later, which contains fixes for this vulnerability. The patch implements proper input validation and sanitization to prevent command injection attacks through the backup functionality.

If immediate patching is not possible, consider the following temporary mitigations:

1. Restrict access to the /interface/main/backup.php endpoint through web server configuration
2. Implement network-level access controls to limit who can access the OpenEMR administration interfaces
3. Monitor system logs for suspicious activity related to the backup functionality
4. Ensure that the web server runs with minimal required privileges

References

1. SonarSource Blog: https://blog.sonarsource.com/openemr-5-0-2-1-command-injection-vulnerability
2. OpenEMR Community Patch Announcement: https://community.open-emr.org/t/openemr-5-0-2-patch-5-has-been-released/15431
3. SonarSource Community Advisory: https://community.sonarsource.com/t/openemr-5-0-2-1-command-injection-vulnerability-puts-health-records-at-risk/33592
4. OpenEMR Patches Documentation: https://www.open-emr.org/wiki/index.php/OpenEMR_Patches