### [CVE-2024-9398](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-9398)
![](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=Product&message=Thunderbird&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=unspecified%3C%20128.3%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Version&message=unspecified%3C%20131%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=External%20protocol%20handlers%20could%20be%20enumerated%20via%20popups&color=brighgreen)

### Description

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

### POC

#### Reference
- https://bugzilla.mozilla.org/show_bug.cgi?id=1881037

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