Studio-42/elfinder - RCE (CVE-2021-23394)

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.