Node-RED-Dashboard - Path Traversal (CVE-2021-3223)

CVE-2021-3223 is a directory traversal vulnerability in Node-RED-Dashboard versions prior to 2.26.2, which allows remote attackers to read arbitrary files on the server by exploiting crafted requests to the ui_base/js/..%2f path. This flaw could be leveraged to access sensitive information and potentially aid in further attacks against the affected system.

CrowdSec has been tracking this vulnerability and its exploits since 15th of May 2026.

CrowdSec network observations suggest that most exploitation of CVE-2021-3223 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-2021-3223 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2021-3223 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers exploit this vulnerability by sending requests to URLs containing /ui_base/js/..%2f with encoded directory traversal sequences, allowing unauthorized access to sensitive files such as /etc/passwd or settings.js on Node-RED Dashboard instances.