Fix Unrestricted Resource Consumption in Slim

$app->post('/process-data', function ($request, $response) {
    $data = $request->getParsedBody();
    // VULNERABILITY: No check on the size of the input array or string.
    // A massive JSON body can cause memory exhaustion during processing.
    $result = some_expensive_computation($data);
    return $response->withJson(['status' => 'done']);
});
$app->post(‘/upload’, function ($request, $response) {
$files = $request->getUploadedFiles();
$file = $files[‘avatar’];
// VULNERABILITY: No size validation. Attackers can fill the disk.
$file->moveTo(‘/uploads/’ . $file->getClientFilename());
return $response->withStatus(200);
});

use Slim\Middleware\ContentLengthMiddleware;
use Tuupola\Middleware\RateLimitMiddleware;
// 1. Enforce global Content-Length limits
$app->add(new ContentLengthMiddleware());
// 2. Rate limiting to prevent request flooding
$app->add(new RateLimitMiddleware([
‘limit’ => 50,
‘timeout’ => 3600
]));
$app->post(‘/upload’, function ($request, $response) {
$files = $request->getUploadedFiles();
$file = $files[‘avatar’] ?? null;
if (!$file || $file->getError() !== UPLOAD_ERR_OK) {
    return $response->withStatus(400);
}

// 3. Explicit file size check (e.g., 2MB limit)
if ($file->getSize() > 2097152) {
    return $response->withStatus(413)->write('Payload Too Large');
}

$dest = '/secure/uploads/' . bin2hex(random_bytes(16));
$file->moveTo($dest);
return $response->withStatus(201);
});