# CVE-2023-4220: Chamilo - Arbitrary File Upload

> Live exploitation tracking for CVE-2023-4220 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2023-4220

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 8.1
- **Public exploit available:** Yes
- **Affected products:** Chamilo
- **Weaknesses:** CWE-434 (Unrestricted Upload of File with Dangerous Type)
- **Tags:** web_application

## Description

Unrestricted file upload in big file upload functionality in `/main/inc/lib/javascript/bigupload/inc/bigUpload.php` in Chamilo LMS <= v1.11.24 allows unauthenticated attackers to perform stored cross-site scripting attacks and obtain remote code execution via uploading of web shell.

## CrowdSec analysis

[CVE-2023-4220](https://euvd.enisa.europa.eu/vulnerability/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`.

## Timeline

- 2023-11-28: CVE Published. CVE-2023-4220 is published to NVD.
- 2025-03-05: Rule Released. CrowdSec releases a rule to detect CVE-2023-4220 exploitation attempts against the CrowdSec Network.
- 2025-03-06: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2023-4220 for the first time.

## References

- https://github.com/chamilo/chamilo-lms/commit/3b487a55076fb06f96809b790a35dcdd42f8ec49
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-4220.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2023-4220) follows observed exploitation activity for CVE-2023-4220. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.