CVE-2020-11083
Stored XSS in October
Description
### 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">
How to fix CVE-2020-11083
To remediate CVE-2020-11083, upgrade the affected package to a fixed version below.
- —upgrade to 1.0.466 or later
Is CVE-2020-11083 being exploited?
Low — EPSS is 1.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 1.0.319, < 1.0.466
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.5 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N |