KCFinder Scanner

KCFinder is a web-based file manager used for uploading and managing files on web servers. Developed initially for integration with CKEditor and other web applications, it helps web developers and administrators efficiently manage digital assets. Its usage spans across various sectors including education, business, and personal websites that require user-uploaded content management. As a web application add-on, it simplifies the process of handling files, making it an attractive tool for many developers. Often embedded in content management systems (CMS) and other platforms, KCFinder streamlines the file management process significantly. The primary users of KCFinder typically include web developers, site administrators, and content creators who need a reliable solution for managing web-accessible files.

The exposure vulnerability in KCFinder arises from its potential to be publicly accessible, which can lead to unauthorized actions by attackers. This vulnerability could permit arbitrary file uploads, allowing malicious files to be uploaded to the server. Exposure of KCFinder could also facilitate remote code execution (RCE), which is one of the more severe security risks associated with it. Unauthorized access to KCFinder instances may let attackers exploit sensitive functionalities of the file manager. An exposed KCFinder instance lacks sufficient access controls, easing the path for malicious individuals to exploit the system. This exposure poses significant security risks to web servers, particularly if appropriate security measures are not in place.

In technical terms, the vulnerability is due to inadequate restrictions on public access to KCFinder endpoints. Key vulnerable endpoints include various browse.php files located within the KCFinder installation directories. These script endpoints may allow unauthorized access when left publicly accessible. Verifying the presence of a KCFinder instance often involves checking the HTTP status and specific title tags in the returned web page content. When KCFinder is inadequately shielded, it displays identifiable content that an attacker can use to mount subsequent attacks on the web application. The typical attack vector consists of unauthorized HTTP requests to KCFinder directories, testing for accessible endpoints that should otherwise be restricted.

Exploitation of this vulnerability can lead to severe consequences, including unauthorized file uploads, data theft, and potentially complete server compromise via remote code execution. Malicious actors can upload web shells or other scripts that grant deeper access to the server and all its contents. Such actions can severely compromise the security integrity of the web application. Sensitive data breach, defacement, and complete control over website functionalities by attackers are potential effects of an exploited KCFinder instance. Ultimately, KCFinder exposure can act as a breach point, compromising not only the specific application but potentially the entire network hosting it.

REFERENCES

• https://github.com/sunhater/kcfinder