GHSA-x2pw-9c38-cp2j WWBN AVideo: Missing CSRF Protection on State-Changing JSON Endpoints Enables Forced Comment Creation, Vote Manipulation, and Category Asset Deletion

• Packagist wwbn/avideo: <= 29.0 (no fix yet)

Summary Multiple AVideo JSON endpoints under `objects/` accept state-changing requests via `$_REQUEST`/`$_GET` and persist changes tied to the caller's session user, without any anti-CSRF token, origin check, or referer check. A malicious page visited by a logged-in victim can silently: 1. Cast/flip the victim's like/dislike on any comment (`objects/comments_like.json.php`). 2. Post a comment authored by the victim on any video, with attacker-chosen text (`objects/commentAddNew.json.php`). 3. Delete assets from any category (`objects/categoryDeleteAssets.json.php`) when the victim has category management rights. Each endpoint is reachable from a browser via a simple `` tag or form submission, so exploitation only requires the victim to load an attacker-controlled HTML resource. Details AVideo exposes a helper, `forbidIfIsUntrustedRequest()` (`objects/functionsSecurity.php:138`), that rejects cross-origin requests when the `Referer`/`Origin` does not match `webSiteRootURL`. It is only invoked in one file in the tree — `objects/userUpdate.json.php:18` — and is *not* applied to the endpoints below. There is also an `isGlobalTokenValid()` helper (`objects/functions.php:2313`) intended for CSRF-style token checks; none of the affected endpoints call it. `allowOrigin()` only sets CORS response headers and does not prevent cookie-bearing top-level or image requests from reaching the server. 1. `objects/comments_like.json.php` — CSRF → forced like/dislike ```php // objects/comments_like.json.php 15: if (empty($_POST['comments_id']) && !empty($_GET['comments_id'])) { 16: $_POST['comments_id'] = $_GET['comments_id']; 17: } 18: 19: $like = new CommentsLike($_GET['like'], $_POST['comments_id']); 20: echo json_encode(CommentsLike::getLikes($_POST['comments_id'])); ``` The endpoint deliberately promotes `$_GET['comments_id']` to `$_POST['comments_id']` so the call works for either verb. `CommentsLike::__construct` (`objects/comments_like.php:18`) reads `User::getId()`, calls `load()` to fetch any prior vote, then `setLike()` + `save()` — issuing an `INSERT`/`UPDATE` on `comments_likes` keyed to the session user (`objects/comments_like.php:70-89`). There is no token check and no origin check. 2. `objects/commentAddNew.json.php` — CSRF → forced comment posting ```php // objects/commentAddNew.json.php 34: if (!User::canComment()) { 35: $obj->msg = __("Permission denied"); 36: die(json_encode($obj)); 37: } ... 117: $objC = new Comment($_REQUEST['comment'], $_REQUEST['video']); 118: $objC->setComments_id_pai($_REQUEST['comments_id']); ... 124: $obj->comments_id = $objC->save(); ``` All inputs come from `$_REQUEST`, so GET is fully supported. The only gate is `User::canComment()`, which is true for ordinary logged-in users. `isCommentASpam()` (lines 39–97) is a per-session rate limiter, not a CSRF defense — it accounts the victim's own session bucket, so it does not block a single forged write. The comment is persisted under the victim's `users_id` via `$objC->save()`. 3. `objects/categoryDeleteAssets.json.php` — CSRF → forced deletion of category assets ```php // objects/categoryDeleteAssets.json.php 14: $obj->id = intval(@$_REQUEST['id']); 15: 16: if (!Category::canCreateCategory()) { 17: $obj->msg = __("Permission denied"); 18: die(json_encode($obj)); 19: } 20: 21: if (!Category::deleteAssets($obj->id)) { 22: $obj->error = false; 23: ... ``` State-destroying operation reachable by GET with no CSRF defense. The attacker can enumerate category ids with a loop of `` tags — every one fires a credentialed request. Root cause (shared) All three endpoints follow the same pattern: `objects/*.json.php` handler that (a) reads mutating parameters from `$_REQUEST`/`$_GET`, (b) performs authorization against the victim's session, and (c) writes to the database — without calling `forbidIfIsUntrustedRequest()`, without validating a CSRF token, and without any `SameSite` mitigation in the session cookie set by AVideo's auth layer. Any logged-in victim loading an attacker-controlled HTML resource is sufficient. PoC Preconditions: attacker controls a page the victim loads while logged into the target AVideo instance. Cookies are sent by default on cross-site ``/top-level GETs. Variant A — comments_like.json.php (force a downvote on comment id 10) Attacker page: ```html ``` Manual verification: ```bash curl -b 'PHPSESSID=' \ 'https://victim.example.com/objects/comments_like.json.php?like=-1&comments_id=10' → {"comments_id":10,"likes":...,"dislikes":...,"myVote":-1} Row inserted/updated in `comments_likes` with users_id = victim. ``` Variant B — commentAddNew.json.php (force victim to post a phishing comment on video 123) Attacker page: ```html ``` Manual verification: ```bash curl -b 'PHPSESSID=' \ 'https://victim.example.com/objects/commentAddNew.json.php?comment=phish&video=123' → {"error":false,"comments_id":,"msg":"Your comment has been saved!",...} ``` Variant C — categoryDeleteAssets.json.php (force a category admin to delete assets on category 1) Attacker page (enumerate several ids): ```html ``` Manual verification: ```bash curl -b 'PHPSESSID=' \ 'https://victim.example.com/objects/categoryDeleteAssets.json.php?id=1' → {"error":false,"msg":"","id":1} Assets for category 1 are removed. ``` Impact • Integrity of social signals: Attackers can flip any logged-in user's likes/dislikes to upvote attacker comments or downvote legitimate comments at scale (driven by whichever users visit the attacker page). Because the endpoint accepts `like=-1|0|1`, arbitrary vote states can be forced. • Identity abuse via forced comments: An attacker can cause any logged-in user with comment permission to "post" attacker-controlled text on any video. This enables impersonation, phishing link injection under a trusted account, harassment of third parties in a victim's name, and (if the victim is a moderator/admin) endorsement-shaped content in a privileged voice. • Data loss: Any user with `canCreateCategory()` who visits an attacker page can be made to silently delete assets belonging to arbitrary categories. Since category ids are small integers, a loop of `` tags can cover the full category space in one page load. No special configuration is required; AVideo's default session cookie lacks a `SameSite=Lax/Strict` protection that would independently blunt the attack, and none of the affected endpoints verifies origin or token. Recommended Fix 1. Call the existing `forbidIfIsUntrustedRequest()` helper at the top of every mutating `objects/*.json.php` handler (the same pattern already used in `objects/userUpdate.json.php`): ```php // objects/comments_like.json.php (add near line 9) require_once $global['systemRootPath'] . 'objects/functionsSecurity.php'; forbidIfIsUntrustedRequest(); // objects/commentAddNew.json.php (add after configuration.php include) require_once $global['systemRootPath'] . 'objects/functionsSecurity.php'; forbidIfIsUntrustedRequest(); // objects/categoryDeleteAssets.json.php (add after configuration.php include) require_once $global['systemRootPath'] . 'objects/functionsSecurity.php'; forbidIfIsUntrustedRequest(); ``` 2. Require `$_SERVER['REQUEST_METHOD'] === 'POST'` (or `DELETE`) for state-changing operations and stop promoting `$_GET['comments_id']` → `$_POST['comments_id']` in `comments_l…