CVE-2020-11083

In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.

In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.

### Impact A user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. ### Patches Issue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the `backend.allow_unsafe_markdown` permission. ### Workarounds Apply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin). ### References Reported by [Sivanesh Ashok](https://stazot.com/) ### For more information If you have any questions or comments about this advisory: * Email us at [hello@octobercms.com](mailto:hello@octobercms.com) ### Threat assessment: <img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">

### Impact A user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. ### Patches Issue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the `backend.allow_unsafe_markdown` permission. ### Workarounds Apply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin). ### References Reported by [Sivanesh Ashok](https://stazot.com/) ### For more information If you have any questions or comments about this advisory: * Email us at [hello@octobercms.com](mailto:hello@octobercms.com) ### Threat assessment: <img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">

En octubre, desde versión 1.0.319 y anterior a versión 1.0.466, un usuario con acceso a un FormWidget de descuento que almacena datos persistentemente podría crear un ataque de tipo XSS almacenado contra sí mismo y cualquier otro usuario con acceso al HTML generado desde el campo. Esto se ha corregido en 1.0.466. Para los usuarios del plugin RainLab.Blog, esto también se ha corregido en 1.4.1