GitHub Security Advisory: GHSA-w4hp-w536-jg64
Package: wwbn/avideo (COMPOSER)
Severity: MODERATE (CVSS 6.4)
CWE: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Vulnerable versions: <= 26.0
Patched in: unpatched

Summary: AVideo: DOM XSS via Unsanitized Display Name in WebSocket Call Notification

Details:
## Summary

The AVideo YPTSocket plugin's caller feature renders incoming call notifications using the jQuery Toast Plugin, passing the caller's display name directly as the `heading` parameter. The toast plugin constructs the heading as raw HTML (`'<h2>' + heading + '</h2>'`) and inserts it into the DOM via jQuery's `.html()` method, which parses and executes any embedded HTML or script content. An attacker can set their display name to an XSS payload and trigger code execution on any online user's browser simply by initiating a call - no victim interaction is required beyond being connected to the WebSocket.

## Details

When a call notification arrives via WebSocket, the caller's identity is extracted from the JSON message:

```javascript
// plugin/YPTSocket/caller.js:73
userIdentification = json.from_identification;
```

This value is passed directly to the jQuery Toast Plugin as the heading:

```javascript
// plugin/YPTSocket/caller.js:89
heading: userIdentification,
```

Inside the jQuery Toast Plugin, the heading is rendered as raw HTML:

```javascript
// node_modules/jquery-toast-plugin/src/jquery.toast.js:60
// Constructs: '<h2>' + heading + '</h2>'
// Then inserts via .html()
```

jQuery's `.html()` method parses the string as HTML and executes any script-bearing elements (such as `<img onerror>`, `<svg onload>`, etc.).

There is a secondary injection vector in the same file where the full JSON message is placed inside a single-quoted `onclick` attribute:

```javascript
// plugin/YPTSocket/caller.js:121-123
imageAndButton += '<button class="btn btn-danger btn-circle incomeCallBtn" onclick=\'hangUpCall(' + JSON.stringify(json) + ')\'><i class="fas fa-phone-slash"></i></button>';
if (isJsonReceivingCall(json)) {
    imageAndButton += '<button class="btn btn-success btn-circle incomeCallBtn" onclick=\'acceptCall(' + JSON.stringify(json) + ')\'><i class="fas fa-phone"></i></button>';
```

`JSON.stringify(json)` is placed inside a single-quoted `onclick` attribute. If any field in `json` contains a single quote, it breaks the attribute boundary and allows attribute injection.

## Proof of Concept

**Important note on the attack vector:** `User::setName()` at `objects/user.php:2069` uses `strip_tags()`, so the display name IS sanitized on the server side when set through the normal UI or API. However, the WebSocket server relays call messages as-is without server-side validation of the `from_identification` field. A malicious WebSocket client can send any `from_identification` value directly over the WebSocket protocol, bypassing the server-side sanitization entirely. The attack requires a custom WebSocket client, not the normal UI.

**Step 1: Connect a malicious WebSocket client and send a forged call message**

The following JavaScript connects directly to the AVideo WebSocket server and sends a call message with an XSS payload in the `from_identification` field:

```javascript
// Malicious WebSocket client - bypasses server-side strip_tags