### [CVE-2018-18509](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-18509)
![](https://img.shields.io/static/v1?label=Product&message=Thunderbird&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3C%2060.5.1%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=S%2FMIME%20signature%20spoofing&color=brighgreen)

### Description

A flaw during verification of certain S/MIME signatures causes emails to be shown in Thunderbird as having a valid digital signature, even if the shown message contents aren't covered by the signature. The flaw allows an attacker to reuse a valid S/MIME signature to craft an email message with arbitrary content. This vulnerability affects Thunderbird < 60.5.1.

### POC

#### Reference
- http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html
- http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html

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