Chamilo - Arbitrary File Upload (CVE-2023-4220)

CVE-2023-4220 is a vulnerability in Chamilo LMS related to the big file upload functionality, allowing unauthenticated attackers to upload arbitrary files, potentially leading to remote code execution and stored cross-site scripting attacks.

CrowdSec has been tracking this vulnerability and its exploits since 5th of March 2025.

CrowdSec network observations suggest that most exploitation of CVE-2023-4220 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental. Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2023-4220 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2023-4220 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Observed attack attempts are characterized by requests to URLs containing /main/inc/lib/javascript/bigupload/inc/bigupload.php.