### [CVE-2019-17016](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-17016)
![](https://img.shields.io/static/v1?label=Product&message=Firefox%20ESR&color=blue)
![](https://img.shields.io/static/v1?label=Product&message=Firefox&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Bypass%20of%20%40namespace%20CSS%20sanitization%20during%20pasting&color=brighgreen)

### Description

When pasting a &lt;style&gt; tag from the clipboard into a rich text editor, the CSS sanitizer incorrectly rewrites a @namespace rule. This could allow for injection into certain types of websites resulting in data exfiltration. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

### POC

#### Reference
- http://packetstormsecurity.com/files/155912/Slackware-Security-Advisory-mozilla-thunderbird-Updates.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=1599181

#### Github
- https://github.com/ARPSyndicate/cvemon