FacturaScripts: Path traversal in UploadedFile::move() via getClientOriginalName() — arbitrary file write outside MyFiles/ leading to RCE

Summary

FacturaScripts\Core\UploadedFile::move($destiny, $destinyName) concatenates $destiny and $destinyName without normalizing the resulting path. Every caller in the codebase passes UploadedFile::getClientOriginalName() — the unsanitized client-supplied filename — as $destinyName, so an authenticated user submitting a filename containing ../ segments can write the uploaded content to any directory writable by the web-server user, escaping the intended MyFiles/ location.

Because the shipped htaccess-sample (the documented production Apache configuration) excludes Dinamic/Assets/ and node_modules/ from the index.php rewrite, files written into those directories are served directly by Apache. Combined with .htaccess not being in BLOCKED_EXTENSIONS, the primitive escalates from arbitrary file write to remote code execution.

Vulnerable Code

Core/UploadedFile.php:

private const BLOCKED_EXTENSIONS = ['phar', 'php', 'php3', 'php4', 'php5', 'php7', 'php8', 'pht', 'phtml', 'phps'];

public function move(string $destiny, string $destinyName): bool
{
    if (!$this->isValid()) {
        return false;
    }
    if (substr($destiny, -1) !== DIRECTORY_SEPARATOR) {
        $destiny .= DIRECTORY_SEPARATOR;
    }
    return $this->test ?
        rename($this->tmp_name, $destiny . $destinyName) :
        move_uploaded_file($this->tmp_name, $destiny . $destinyName);
}

public function getClientOriginalName(): string
{
    return $this->name ?? '';
}

isValid() only checks the extension blocklist, the upload error code, and is_uploaded_file() — it never inspects the filename for directory separators or .. segments.

Six call sites pass the raw client filename straight into move():

• Core/Controller/ApiUploadFiles.php:58 — POST /api/3/uploadfiles
• Core/Controller/ApiAttachedFiles.php:136 — POST /api/3/attachedfiles
• Core/Lib/Widget/WidgetFile.php:84 — every form using a file widget
• Core/Lib/Widget/WidgetLibrary.php:215 — library widget upload
• Core/Lib/ExtendedController/DocFilesTrait.php:51 — document files trait
• Core/Controller/AdminPlugins.php:260 — plugin (zip) upload

Representative sink — Core/Controller/ApiUploadFiles.php:56-79:

private function uploadFile(UploadedFile $uploadFile): ?AttachedFile
{
    if (false === $uploadFile->isValid()) {
        return null;
    }
    $destiny = FS_FOLDER . '/MyFiles/';
    $destinyName = $uploadFile->getClientOriginalName();
    if (file_exists($destiny . $destinyName)) {
        $destinyName = mt_rand(1, 999999) . '_' . $destinyName;
    }
    if ($uploadFile->move($destiny, $destinyName)) {
        ...
    }
}

Shipped htaccess-sample (production Apache rules):

   RewriteEngine On
   RewriteBase /
   RewriteCond %{REQUEST_URI} !Dinamic/Assets/ [NC]
   RewriteCond %{REQUEST_URI} !node_modules/ [NC]
   RewriteRule . index.php [L]

Apache therefore serves any file under Dinamic/Assets/ directly, bypassing index.php entirely.

PoC

Step 1 — Static reproduction of the file-write primitive

The following script replicates UploadedFile::move()'s rename() path verbatim inside a sandboxed temp directory. It does not run any payload — it only demonstrates that the destination escapes MyFiles/ when the filename contains ../.