GHSA-v3ph-2q5q-cg88

### Summary In the HAX site editor, users can create a website block to load another site in an iframe. The application allows users to supply a target URL in the website block. When the HAX site is visited, the client's browser will query the supplied URL. ### Affected Resources - [Operations.php:868](https://github.com/haxtheweb/haxcms-php/blob/master/system/backend/php/lib/Operations.php#L868) - `https://<site>/<user>/system/api/saveNode` ### PoC 1. Set the URL in an iframe pointing to an attacker-controlled server running Responder  2. Once another user visits the site, they are prompted to sign in.  3. If a user inputs credentials, the username and password hash are outputted in Responder.  ### Impact An authenticated attacker can create a HAX site with a website block pointing at an attacker-controlled server running Responder or a similar tool. The attacker can then conduct a phishing attack by convincing another user to visit their malicious HAX site to harvest credentials.