WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `aVideoEncoderChunk.json.php` endpoint is a completely standalone PHP script with no authentication, no framework includes, and no resource limits. An unauthenticated remote attacker can send arbitrary POST data which is written to persistent temp files in `/tmp/` with no size cap, no rate limiting, and no cleanup mechanism. This allows trivial disk space exhaustion leading to denial of service of the entire server. Commit 33d1bae6c731ef1682fcdc47b428313be073a5d1 contains a patch.

Affected: Packagist: wwbn/avideo

## Summary

The `aVideoEncoderChunk.json.php` endpoint is a completely standalone PHP script with no authentication, no framework includes, and no resource limits. An unauthenticated remote attacker can send arbitrary POST data which is written to persistent temp files in `/tmp/` with no size cap, no rate limiting, and no cleanup mechanism. This allows trivial disk space exhaustion leading to denial of service of the entire server.

## Details

The file `objects/aVideoEncoderChunk.json.php` (25 lines total) operates entirely outside the AVideo framework:

```php // objects/aVideoEncoderChunk.json.php — full file <?php header('Access-Control-Allow-Origin: *'); // Line 2: CORS wildcard header('Content-Type: application/json'); $obj = new stdClass(); $obj->file = tempnam(sys_get_temp_dir(), 'YTPChunk_'); // Line 5: creates /tmp/YTPChunk_XXXXXX

$putdata = fopen("php://input", "r"); // Line 7: reads raw POST body $fp = fopen($obj->file, "w");

while ($data = fread($putdata, 1024 * 1024)) { // Line 12: 1MB chunks, no limit fwrite($fp, $data); }

fclose($fp); fclose($putdata); sleep(1); $obj->filesize = filesize($obj->file);

$json = json_encode($obj); die($json); // Line 25: returns {"file":"/tmp/YTPChunk_abc123","filesize":104857600} ```

The vulnerability chain:

1. **No authentication**: The script includes no session handling, no `require_once` of the framework, no `useVideoHashOrLogin()`, no `canUpload()…