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. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2021-23394 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2021-23394 is currently experiencing high visibility and active exploitation across the internet.

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.