Squidex is an open source headless CMS and content management hub. Affected versions are subject to an arbitrary file write vulnerability in the backup restore feature which allows an authenticated attacker to gain remote code execution (RCE). Squidex allows users with the `squidex.admin.restore` permission to create and restore backups. Part of these backups are the assets uploaded to an App. For each asset, the backup zip archive contains a `.asset` file with the actual content of the asset as well as a related `AssetCreatedEventV2` event, which is stored in a JSON file. Amongst other things, the JSON file contains the event type (`AssetCreatedEventV2`), the ID of the asset (`46c05041-9588-4179-b5eb-ddfcd9463e1e`), its filename (`test.txt`), and its file version (`0`). When a backup with this event is restored, the `BackupAssets.ReadAssetAsync` method is responsible for re-creating the asset. For this purpose, it determines the name of the `.asset` file in the zip archive, reads its…

Squidex is an open source headless CMS and content management hub. Affected versions are missing origin verification in a postMessage handler which introduces a Cross-Site Scripting (XSS) vulnerability. The editor-sdk.js file defines three different class-like functions, which employ a global message event listener: SquidexSidebar, SquidexWidget, and SquidexFormField. The registered event listener takes some action based on the type of the received message. For example, when the SquidexFormField receives a message with the type valueChanged, the value property is updated. The SquidexFormField class is for example used in the editor-editorjs.html file, which can be accessed via the public wwwroot folder. It uses the onValueChanged method to register a callback function, which passes the value provided from the message event to the editor.render. Passing an attacker-controlled value to this function introduces a Cross-Site Scripting (XSS) vulnerability.