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.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2023-4220 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. CrowdSec data also reveals a clear uptick in attacks involving CVE-2023-4220 over the past week. Activity is above the usual baseline, suggesting growing attention from attackers. This may reflect rising awareness, recent exploit releases, or expanded targeting efforts.

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