{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "wwbn/avideo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "26.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33492"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-384"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-20T20:49:23Z",
    "nvd_published_at": "2026-03-23T16:16:49Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nAVideo\u0027s `_session_start()` function accepts arbitrary session IDs via the `PHPSESSID` GET parameter and sets them as the active PHP session. A session regeneration bypass exists for specific blacklisted endpoints when the request originates from the same domain. Combined with the explicitly disabled session regeneration in `User::login()`, this allows a classic session fixation attack where an attacker can fix a victim\u0027s session ID before authentication and then hijack the authenticated session.\n\n## Details\n\nThe vulnerability is a chain of three weaknesses that together enable session fixation:\n\n### 1. Attacker-controlled session ID acceptance (`objects/functionsPHP.php:344-367`)\n\n```php\nfunction _session_start(array $options = [])\n{\n    // ...\n    if (isset($_GET[\u0027PHPSESSID\u0027]) \u0026\u0026 !_empty($_GET[\u0027PHPSESSID\u0027])) {\n        $PHPSESSID = $_GET[\u0027PHPSESSID\u0027];\n        // ...\n        if (!User::isLogged()) {\n            if ($PHPSESSID !== session_id()) {\n                _session_write_close();\n                session_id($PHPSESSID);   // \u003c-- sets session to attacker\u0027s ID\n            }\n            $session = @session_start($options);  // \u003c-- starts with attacker\u0027s ID\n```\n\nThe code reads `$_GET[\u0027PHPSESSID\u0027]` and programmatically calls `session_id($PHPSESSID)`, which bypasses both `session.use_only_cookies` and `session.use_strict_mode` PHP settings since the session ID is set via the PHP API, not via cookie/URL handling.\n\n### 2. Session regeneration bypass for blacklisted endpoints (`objects/functionsPHP.php:375-378`, `objects/functions.php:3100-3116`)\n\n```php\n// functionsPHP.php:375-378\nif (!blackListRegenerateSession()) {\n    _session_regenerate_id();  // \u003c-- SKIPPED when blacklisted + same-domain\n}\n```\n\n```php\n// functions.php:3100-3116\nfunction blackListRegenerateSession()\n{\n    if (!requestComesFromSafePlace()) {\n        return false;\n    }\n    $list = [\n        \u0027objects/getCaptcha.php\u0027,\n        \u0027objects/userCreate.json.php\u0027,\n        \u0027objects/videoAddViewCount.json.php\u0027,\n    ];\n    foreach ($list as $needle) {\n        if (str_ends_with($_SERVER[\u0027SCRIPT_NAME\u0027], $needle)) {\n            return true;  // \u003c-- regeneration skipped for these endpoints\n        }\n    }\n    return false;\n}\n```\n\nThe `requestComesFromSafePlace()` check at `objects/functionsSecurity.php:182` only verifies that `HTTP_REFERER` matches the AVideo domain. When a victim clicks a link from within the AVideo platform (e.g., in a comment or video description), the browser naturally sets the Referer to the AVideo domain, satisfying this check.\n\n### 3. Disabled session regeneration on login (`objects/user.php:1315-1317`)\n\n```php\n// Call custom session regenerate logic\n// this was regenerating the session all the time, making harder to save info in the session\n//_session_regenerate_id();  // \u003c-- COMMENTED OUT\n```\n\nThe session regeneration after authentication is explicitly disabled. This means the session ID persists unchanged through the login transition, which is the fundamental requirement for session fixation to succeed.\n\n### Amplifying factors\n\n- `objects/phpsessionid.json.php` exposes session IDs to any same-origin JavaScript without authentication (line 12: `$obj-\u003ephpsessid = session_id()`)\n- `view/js/session.js` stores the session ID in a global `window.PHPSESSID` variable and logs it to console (line 15)\n- No session-to-IP or session-to-user-agent binding exists (verified via codebase search)\n\n## PoC\n\n### Step 1: Attacker obtains a session ID\n\n```bash\n# Attacker visits the site to get a valid session ID\ncurl -v https://target.example.com/ 2\u003e\u00261 | grep \u0027set-cookie.*PHPSESSID\u0027\n# Response: Set-Cookie: PHPSESSID=attacker_known_session_id; ...\n```\n\n### Step 2: Attacker injects a link on the platform\n\nThe attacker posts a comment on a video or creates content containing a link:\n\n```\nhttps://target.example.com/objects/getCaptcha.php?PHPSESSID=attacker_known_session_id\n```\n\nThis can be placed in a video comment, video description, user bio, or forum post \u2014 anywhere AVideo renders user-provided links.\n\n### Step 3: Victim clicks the link while browsing AVideo\n\nWhen the victim clicks the link from within the AVideo platform:\n1. Browser sets `Referer: https://target.example.com/...` (same-domain)\n2. `_session_start()` processes `$_GET[\u0027PHPSESSID\u0027]`, victim is not logged in, so `session_id(\u0027attacker_known_session_id\u0027)` is called\n3. `blackListRegenerateSession()` returns `true` (script is `getCaptcha.php` + same-domain Referer)\n4. `_session_regenerate_id()` is **skipped**\n5. Victim\u0027s session is now fixed to `attacker_known_session_id`\n\n### Step 4: Victim logs in\n\nThe victim navigates to the login page and authenticates. `User::login()` populates `$_SESSION[\u0027user\u0027]` but does NOT regenerate the session ID (line 1317 is commented out).\n\n### Step 5: Attacker hijacks the authenticated session\n\n```bash\n# Attacker uses the known session ID to access victim\u0027s account\ncurl -b \"PHPSESSID=attacker_known_session_id\" https://target.example.com/objects/user.php?userAPI=1\n# Response: victim\u0027s user data, confirming session hijack\n```\n\n## Impact\n\n- **Full account takeover**: An attacker can hijack any user\u0027s authenticated session, including administrator accounts\n- **Data access**: Full access to the victim\u0027s videos, private content, messages, and personal information\n- **Privilege escalation**: If the victim is an admin, the attacker gains full administrative control over the AVideo instance\n- **Lateral actions**: The attacker can perform any action as the victim \u2014 upload/delete content, modify settings, access admin panel\n\n## Recommended Fix\n\n### Fix 1: Re-enable session regeneration on login (`objects/user.php:1317`)\n\n```php\n// Replace the commented-out line:\n//_session_regenerate_id();\n\n// With:\n_session_regenerate_id();\n```\n\nThis is the most critical fix. Session regeneration on authentication transition is a fundamental defense against session fixation (OWASP recommendation).\n\n### Fix 2: Remove GET-based session ID acceptance (`objects/functionsPHP.php:344-383`)\n\nRemove or restrict the `$_GET[\u0027PHPSESSID\u0027]` handling entirely. If it is needed for specific use cases (e.g., CAPTCHA), validate the session ID against a server-side token rather than blindly accepting arbitrary values:\n\n```php\n// Instead of accepting any GET PHPSESSID, remove this block entirely.\n// If CAPTCHA requires session continuity, pass a CSRF token instead.\nif (isset($_GET[\u0027PHPSESSID\u0027]) \u0026\u0026 !_empty($_GET[\u0027PHPSESSID\u0027])) {\n    // REMOVED: Do not accept session IDs from URL parameters\n}\n```\n\n### Fix 3: Remove session ID exposure (`objects/phpsessionid.json.php`, `view/js/session.js`)\n\nThe `phpsessionid.json.php` endpoint and the `session.js` global variable negate the `httponly` cookie flag. If JavaScript needs to reference the session for AJAX requests, the browser automatically includes session cookies \u2014 there is no need to expose the session ID value to JavaScript.",
  "id": "GHSA-x3pr-vrhq-vq43",
  "modified": "2026-03-25T20:31:06Z",
  "published": "2026-03-20T20:49:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-x3pr-vrhq-vq43"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33492"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WWBN/AVideo/commit/5647a94d79bf69a972a86653fe02144079948785"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/WWBN/AVideo"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "AVideo has Session Fixation via GET PHPSESSID Parameter With Disabled Login Session Regeneration"
}