CVE-2026-104069 in HortusFox
Summary
by MITRE • 10/06/2026
HortusFox before 6.2 contains a remote code execution vulnerability in ThemeModule::startImport() where an uploaded ZIP archive is extracted directly into the public web root before any validation of file names, extensions, or content is performed. An authenticated administrator can upload a crafted theme archive containing a PHP file and an .htaccess file to re-enable execution, then request it under the themes directory to execute arbitrary OS commands as the web-server user.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified in HortusFox versions prior to 6.2 represents a critical remote code execution flaw rooted in insecure file handling practices within the ThemeModule::startImport() function. This specific weakness allows an authenticated administrator, who possesses legitimate access credentials but potentially malicious intent or whose account has been compromised, to upload a specially crafted ZIP archive that is processed without adequate security controls. The core technical failure lies in the sequence of operations performed by the application during theme importation. Instead of validating the contents of the uploaded file before extraction, the system proceeds directly to unzip the archive into the public web root directory. This lack of pre-validation means that there are no checks applied to ensure that contained files have safe extensions, such as excluding executable script languages like PHP from being placed in directories intended for static assets or theme configurations where execution is typically disabled by default server configuration.
The exploitation mechanism relies on two key components within the crafted archive: a malicious PHP file and an .htaccess directive. By placing a PHP file directly into the web-accessible themes directory, the attacker introduces executable code to the environment. However, modern web servers like Apache or Nginx are typically configured to prevent direct execution of scripts in such directories for security reasons. To bypass this default protection, the attacker includes an .htaccess file within the ZIP archive that explicitly re-enables PHP execution for that specific directory path. When the administrator uploads and imports this theme package, the application extracts both files into the public web root without question. The presence of the .htaccess file effectively alters the server's configuration at runtime, creating a backdoor where any request to the themes directory will now process PHP code as executable scripts rather than static content.
Once the malicious files are in place and the execution context is restored via the manipulated .htaccess file, an attacker can trigger arbitrary operating system commands by sending HTTP requests to the uploaded PHP script. Because this code executes within the context of the web server user account, typically a low-privilege service account such as www-data or nginx, the immediate impact may be limited in terms of direct root access but remains severe for application compromise. The attacker can achieve full control over the web application's data and functionality, potentially leading to further lateral movement within the network if the web server user has broader permissions than intended. This scenario aligns with CWE-434, which describes the unrestricted upload of files with dangerous types, as well as CWE-94, indicating improper control of generation of code or script, specifically when input is not properly sanitized before being used in a way that allows command execution.
From an offensive security perspective, this vulnerability maps to several techniques within the MITRE ATT&CK framework. The initial upload and extraction phase corresponds to T1505.003, Server Component Binary Implanting, where attackers implant malicious components into legitimate server software. The use of .htaccess to enable execution is a form of configuration change that facilitates persistence or privilege escalation depending on the context, often associated with T1222, File and Directory Permissions Modification. Furthermore, the final stage of executing arbitrary commands via the web shell falls under T1059, Command and Scripting Interpreter, specifically targeting PHP environments. These mappings highlight how a single input validation failure can cascade into multiple stages of an attack chain, from initial access to execution.
Mitigation strategies for this vulnerability must focus on implementing strict file upload controls and secure coding practices within the application logic. The most effective remediation is to enforce server-side validation that checks file extensions against a whitelist of allowed types before any extraction occurs. Additionally, files should be extracted into a non-web-accessible directory first, where they can be scanned for malicious content or structural integrity issues before being moved to their final destination if deemed safe. Implementing Content-Disposition headers and ensuring that uploaded files are stored outside the document root entirely would also prevent direct execution via HTTP requests. For organizations still running HortusFox versions prior to 6.2, upgrading to version 6.2 or later is essential as this release addresses these specific flaws in the ThemeModule import process. Until an upgrade can be performed, administrators should restrict access to administrative interfaces using strong authentication mechanisms and network segmentation to reduce the risk of unauthorized uploads exploiting this code execution pathway.