### [CVE-2021-43540](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43540)
![](https://img.shields.io/static/v1?label=Product&message=Firefox&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=unspecified%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=WebExtensions%20could%20have%20installed%20persistent%20ServiceWorkers&color=brightgreen)

### Description

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.

### POC

#### Reference
- https://bugzilla.mozilla.org/show_bug.cgi?id=1636629

#### Github
No PoCs found on GitHub currently.