CVE-2026-102427 in CCK Extension
Summary
by MITRE • 09/30/2026
Joomla Extension - ordasoft.com - Unauthenticated Remote Code Execution in OrdaSoft Joomla CCK < 8.3.16 - site/uploader.php is reached through the component’s normal frontend routing (task=getContent), a task with no authentication or ACL check anywhere in the dispatch chain. The handler validates the uploaded file’s content with a real magic-byte MIME check, but the extension allow-list that would otherwise restrict the saved file’s extension was present in the source and commented out. The saved file’s extension was taken directly from the attacker-supplied filename with no validation, and the file was written to a path directly under the Joomla web root that is executed by the PHP handler. An image/PHP polyglot, a file whose header bytes satisfy the MIME check with PHP source appended after, passed the content check while carrying a .php extension of the attacker’s choosing.
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified in OrdaSoft Joomla CCK versions prior to 8.3.16 represents a critical unauthenticated remote code execution flaw rooted in improper input validation and insecure file handling mechanisms within the component's frontend interface. The attack vector is accessible through standard web routing by invoking the task parameter set to getContent, which maps directly to the site/uploader.php script. Crucially, this endpoint operates without any authentication checks or access control list enforcement, allowing unauthenticated actors to interact with the upload functionality as if they were legitimate users. This lack of authorization controls means that any internet user can trigger the file processing logic, significantly expanding the attack surface and lowering the barrier for exploitation.
The core technical flaw lies in a discrepancy between content validation and extension handling during the file upload process. The application implements a robust check by verifying the magic bytes of the uploaded file to ensure it matches an expected MIME type, such as image/jpeg or similar valid formats. However, while this mechanism successfully validates the internal structure of the file data, it fails to enforce restrictions on the filename extension used for saving the file. Although source code analysis reveals that a whitelist restricting allowed extensions was present in the original development files, it has been commented out and is therefore inactive during runtime execution. Consequently, the system relies entirely on the attacker-supplied filename to determine the saved file's extension without performing any secondary validation or sanitization steps.
This architectural weakness enables the creation of an image/PHP polyglot payload that bypasses both security controls simultaneously. By crafting a file with valid magic bytes corresponding to an allowed MIME type, such as an image header, and appending PHP source code after these bytes, an attacker can satisfy the content validation check while retaining control over the final filename extension. Since the application accepts the .php extension from the user input without verification, the polyglot is saved directly into a directory under the Joomla web root that is configured to execute PHP scripts. This results in the persistence of malicious code on the server filesystem in a location where it can be invoked by any subsequent HTTP request targeting that specific file path.
The operational impact of this vulnerability is severe, resulting in complete remote code execution with the privileges of the web server process. Once the polyglot script is uploaded and saved as a PHP file, an attacker can execute arbitrary system commands, access sensitive database credentials stored in configuration files, modify or exfiltrate website content, and potentially pivot to attack other systems within the internal network depending on the isolation level of the web server environment. This type of vulnerability aligns with CWE-434, which describes the unrestricted upload of file with dangerous type, as well as CWE-20, indicating improper input validation where external data is accepted without sufficient verification. Furthermore, from a tactical perspective, this exploitation technique corresponds to ATT&CK T1505.003, specifically Server Component Addition, and T1059.004 for Command and Scripting Interpreter: PHP, highlighting the direct path from file upload to code execution.
Mitigation strategies must address both the immediate technical flaw and broader security hygiene practices. The most effective remediation is to upgrade OrdaSoft Joomla CCK to version 8.3.16 or later, where this specific logic error has been resolved by re-enforcing extension whitelists and ensuring that file extensions are validated against a strict allowlist rather than trusting user input. In the interim, administrators should implement server-side restrictions using web server configurations such as Apache's mod_rewrite or Nginx deny rules to prevent execution of PHP files in directories designated for uploads. Additionally, enabling open_basedir restrictions can limit the ability of uploaded scripts to access sensitive system resources outside their intended directory scope. Regular security audits and code reviews are essential to ensure that commented-out security controls do not remain inactive in production environments, as they create a false sense of security while leaving critical vulnerabilities exposed.