GHSA-ffr8-fxhv-fv8h AVideo is Vulnerable to SQL Injection through Subscribe Endpoint via Unsanitized user_id Parameter

• Packagist wwbn/avideo: <= 26.0 (no fix yet)

Summary The `Subscribe::save()` method in `objects/subscribe.php` concatenates the `$this->users_id` property directly into an INSERT SQL query without sanitization or parameterized binding. This property originates from `$_POST['user_id']` in both `subscribe.json.php` and `subscribeNotify.json.php`. An authenticated attacker can inject arbitrary SQL to extract sensitive data from any database table, including password hashes, API keys, and encryption salts. Details The vulnerability exists because of a disconnect between where `intval()` is applied and where the value is used in SQL. Entry points — `objects/subscribe.json.php:40` and `objects/subscribeNotify.json.php:23`: ```php // subscribe.json.php line 40 $subscribe = new Subscribe(0, $_POST['email'], $_POST['user_id'], User::getId()); ``` Constructor stores raw value — `objects/subscribe.php:34`: ```php public function __construct($id, $email = "", $user_id = "", $subscriber_users_id = "") { // ... $this->users_id = $user_id; // Raw $_POST['user_id'], no sanitization $this->subscriber_users_id = $subscriber_users_id; if (empty($this->id)) { $this->loadFromId($this->subscriber_users_id, $user_id, ""); } } ``` `getSubscribeFromID` sanitizes local copies only — `objects/subscribe.php:137-139`: ```php public static function getSubscribeFromID($subscriber_users_id, $user_id, $status = "a"){ $subscriber_users_id = intval($subscriber_users_id); // Local variable only $user_id = intval($user_id); // Local variable only — $this->users_id is NOT affected ``` When `getSubscribeFromID` finds no matching subscription (the attacker simply targets a user_id they haven't subscribed to), `loadFromId()` returns false. The object's `$this->id` remains null, and `$this->users_id` retains the unsanitized injection payload. Vulnerable sink — `objects/subscribe.php:88`: ```php public function save() { if (!empty($this->id)) { // UPDATE path (not reached when $this->id is null) } else { $this->status = 'a'; $sql = "INSERT INTO subscribes (users_id, email, status, ip, created, modified, subscriber_users_id) VALUES ('{$this->users_id}', ..."; // Direct concatenation of injected value } $saved = sqlDAL::writeSql($sql); // Called with NO $formats or $values ``` `sqlDAL::writeSql` provides no protection — `objects/mysql_dal.php:102`: When called without `$formats`/`$values` parameters (as `save()` does), the `eval_mysql_bind()` function at line 636 returns `true` without binding any parameters. The already-concatenated SQL string is passed directly to `$global['mysqli']->prepare()` and `execute()`, executing the injection as the prepared statement itself. PoC Prerequisites: An authenticated session on the target AVideo instance. Step 1: Confirm injection with time-based blind SQLi ```bash Pick a user_id that the current user has NOT subscribed to (e.g., 99999) The SLEEP(5) will cause a ~5 second delay confirming injection curl -s -o /dev/null -w "%{time_total}" \ -b 'PHPSESSID=VALID_SESSION_ID' \ -d "user_id=99999'+AND+SLEEP(5)+AND+'1" \ https://target/objects/subscribe.json.php Expected: ~5 second response time (vs users_id` before use in the constructor, or better yet, use parameterized queries in `save()`. Option 1 — Sanitize in constructor (minimal fix): ```php // objects/subscribe.php, constructor (line 34) • $this->users_id = $user_id; + $this->users_id = intval($user_id); ``` Option 2 — Use parameterized query in save() (recommended): ```php // objects/subscribe.php, save() method (lines 87-90) public function save() { global $global; if (!empty($this->id)) { $sql = "UPDATE subscribes SET status = ?, notify = ?, ip = ?, modified = now() WHERE id = ?"; $saved = sqlDAL::writeSql($sql, "sssi", [$this->status, $this->notify, getRealIpAddr(), $this->id]); } else { $this->status = 'a'; $sql = "INSERT INTO subscribes (users_id, email, status, ip, created, modified, subscriber_users_id) VALUES (?, ?, ?, ?, now(), now(), ?)"; $saved = sqlDAL::writeSql($sql, "isssi", [intval($this->users_id), $this->email, $this->status, getRealIpAddr(), intval($this->subscriber_users_id)]); } ``` Option 2 is strongly recommended as it also fixes the unsanitized `$this->email`, `$this->status`, and `getRealIpAddr()` values in both the INSERT and UPDATE paths, preventing any future injection through those fields.