### Description
A rogue or compromised MeshAgent can inject arbitrary HTML/JavaScript via the osdesc (OS description) field in its coreinfo message. The server stores this value with zero HTML sanitization (meshagent.js:1903 only checks typeof == 'string'). When an admin views the
device details panel, the value is rendered via addDeviceAttribute() → QH() which sets innerHTML, executing the payload in the admin's browser session. The main management UI CSP includes 'unsafe-inline' (webserver.js:7072), so inline event handlers and script execution are unrestricted.
### Technical Details
```javascript
// meshagent.js:1903 -- Agent input, onl
MeshCentral is a full computer management web site. Versions prior to 1.1.21 a cross-site websocket hijacking (CSWSH) vulnerability within the control.ashx endpoint. This component is the primary mechanism used within MeshCentral to perform administrative actions on the server. The vulnerability is exploitable when an attacker is able to convince a victim end-user to click on a malicious link to a page hosting an attacker-controlled site. The attacker can then originate a cross-site websocket connection using client-side JavaScript code to connect to `control.ashx` as the victim user within MeshCentral. Version 1.1.21 contains a patch for thi