GHSA-x2pw-9c38-cp2j WWBN AVideo: Missing CSRF Protection on State-Changing JSON Endpoints Enables Forced Comment Creation, Vote Manipulation, and Category Asset Deletion
SummaryMultiple 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:Cast/flip the victim's like/dislike on any comment (`objects/comments_like.json.php`).Post a comment authored by the victim on any video, with attacker-chosen text (`objects/commentAddNew.json.php`).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 `<img src="…">` tag or form submission, so exploitation only requires the victim to load an attacker-controlled HTML resource.DetailsAVideo 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/dislikeThe 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 postingAll 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 assetsState-destroying operation reachable by GET with no CSRF defense. The attacker can enumerate category ids with a loop of `<img>` 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.PoCPreconditions: attacker controls a page the victim loads while logged into the target AVideo instance. Cookies are sent by default on cross-site `<img>`/top-level GETs.Variant A — comments_like.json.php (force a downvote on comment id 10)Attacker page:Manual verification:Variant B — commentAddNew.json.php (force victim to post a phishing comment on video 123)Attacker page:Manual verification:Variant C — categoryDeleteAssets.json.php (force a category admin to delete assets on category 1)Attacker page (enumerate several ids):Manual verification: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 `<img>` 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 FixCall the existing `forbidIfIsUntrustedRequest()` helper at the top of every mutating `objects/*.json.php` handler (the same pattern already used in `objects/userUpdate.json.php`):Require `$_SERVER['REQUEST_METHOD'] === 'POST'` (or `DELETE`) for state-changing operations and stop promoting `$_GET['comments_id']` → `$_POST['comments_id']` in `comments_like.json.php:15-17`.Validate a per-session CSRF token on all mutating endpoints using the existing `isGlobalTokenValid()` / `getToken()` helpers (`objects/functions.php:2313`), rejecting requests whose `globalToken` is missing or invalid.As defense in depth, set the session cookie with `SameSite=Lax` (or `Strict`) in the AVideo session initialization, so cross-site navigational GETs do not carry the session cookie even if a handler regresses.Applying (1) alone closes all three reported variants; (2)–(4) harden the surface against variants of the same pattern in other `objects/*.json.php` handlers.
CVSS v3.1 score: 5.4