CVE-2020-19364: 
OpenEMR vulnerability analysis and mitigation

OpenEMR 5.0.1 contains a remote code execution vulnerability (CVE-2020-19364) that allows an authenticated attacker to upload and execute malicious PHP scripts through the /controller.php endpoint (OpenEMR GitHub).

The vulnerability exists in the file upload functionality of OpenEMR 5.0.1. An authenticated attacker can exploit this vulnerability by sending a specially crafted POST request to 'http://[HOST]/controller.php?document&upload&patient_id=00&parent_id=4&' to upload malicious PHP code. The CVSS v3.1 base score is 8.8 (HIGH) with the vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

Successful exploitation of this vulnerability allows an authenticated attacker to execute arbitrary PHP code on the target system, potentially leading to complete system compromise with the ability to read, write, and modify data, as well as execute commands on the underlying system (NVD).

The vulnerability requires authentication to exploit, but is relatively straightforward to execute. A proof-of-concept exploit is publicly available that demonstrates the ability to upload and execute malicious PHP files through the vulnerable endpoint (OpenEMR GitHub).

Users should upgrade to a patched version of OpenEMR. If immediate upgrading is not possible, it is recommended to implement strict input validation and file upload restrictions on the affected endpoint (NVD).