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 12th 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. Data from the CrowdSec community also indicates a gradual decrease in attacks targeting CVE-2023-4220. While still present in the wild, exploitation levels have dropped noticeably week-over-week. This may signal that the vulnerability is becoming less relevant or that defenses are improving fast enough for attackers to lose interest.

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