CVEs-PoC/2021/CVE-2021-3618.md

### [CVE-2021-3618](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3618)
![](https://img.shields.io/static/v1?label=Product&message=ALPACA&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=vsftpd%203.0.4%2C%20nginx%201.21.0%2C%20sendmail%208.17%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-295&color=brightgreen)

### Description

ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/R0X4R/Indra
- https://github.com/R0X4R/indraa
- https://github.com/Spyr026/Proyecto-Ciberseguridad
- https://github.com/andreyk444/Ansible-playbook
- https://github.com/bustinjeaber/ansible_playbook_vuln
- https://github.com/eggkingo/polyblog
- https://github.com/rmtec/modeswitcher