[CVE-2018-16468] Loofah XSS Vulnerability

[Rafael Mendonça França]

Hello all,

A medium severity vulnerability has been identified and patched in Loofah v2.2.3, which is a dependency of `rails-html-sanitizer`. This issue has been assigned CVE-2018-16468.

The public notice can be found here:

    https://github.com/flavorjones/loofah/issues/154

To save you a click, I've reproduced the contents of the announcement here.

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# CVE-2018-16468 - Loofah XSS Vulnerability

This issue has been created for public disclosure of an XSS vulnerability that was responsibly reported (independently) by [Shubham Pathak](https://hackerone.com/hackedbrain) and @yasinS (Yasin Soliman).

I'd like to thank [HackerOne](https://hackerone.com/loofah) for providing a secure, responsible mechanism for reporting, and for providing their fantastic service to the Loofah maintainers.


## Severity

Loofah maintainers have evaluated this as [Medium (CVSS3 6.4)](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L).


## Description

In the Loofah gem, through v2.2.2, unsanitized JavaScript may occur in sanitized output when a crafted SVG element is republished.


## Affected Versions

Loofah < v2.2.3.


## Mitigation

Upgrade to Loofah v2.2.3.


## References

* [HackerOne report](https://hackerone.com/reports/429267)


## History of this public disclosure

2018-10-27: disclosure created, all information is embargoed
2018-10-30: embargo ends, full information made available