# CVE-2021-23394: Studio-42/elfinder - RCE

> Live exploitation tracking for CVE-2021-23394 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-2021-23394

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 8.1
- **Public exploit available:** Yes
- **Affected products:** Studio-42 elfinder
- **Weaknesses:** CWE-434 (Unrestricted Upload of File with Dangerous Type)
- **Tags:** php, file_sharing

## Description

The package Studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.

## CrowdSec analysis

[CVE-2021-23394](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-23394) is a remote code execution vulnerability in Studio-42/elfinder versions prior to 2.1.58, allowing attackers to execute arbitrary PHP code via specially crafted .phar files if the server is configured to parse .phar files as PHP. This flaw could be exploited to gain unauthorized access, manipulate data, or take control of the affected system.

CrowdSec has been tracking this vulnerability and its exploits since 14th of January 2026.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2021-23394 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-2021-23394 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.

Attackers exploit endpoints such as `/elFinder/php/connector.minimal.php` and `/elFinder/files/` to upload and execute malicious `.phar` files, enabling remote code execution if the server is configured to parse `.phar` files as PHP.

## Timeline

- 2021-06-13: CVE Published. CVE-2021-23394 is published to NVD.
- 2026-01-14: Rule Released. CrowdSec releases a rule to detect CVE-2021-23394 exploitation attempts against the CrowdSec Network.
- 2026-01-19: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-23394 for the first time.

## References

- https://github.com/Studio-42/elFinder/commit/75ea92decc16a5daf7f618f85dc621d1b534b5e1
- https://github.com/Studio-42/elFinder
- https://blog.sonarsource.com/elfinder-case-study-of-web-file-manager-vulnerabilities/
- https://github.com/Studio-42/elFinder/issues/3295
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-23394.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-23394) follows observed exploitation activity for CVE-2021-23394. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.