cve/2021/CVE-2021-22890.md

### [CVE-2021-22890](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22890)
![](https://img.shields.io/static/v1?label=Product&message=https%3A%2F%2Fgithub.com%2Fcurl%2Fcurl&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Man-in-the-Middle%20(CWE-300)&color=brighgreen)

### Description

curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.

### POC

#### Reference
- https://www.oracle.com//security-alerts/cpujul2021.html

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/indece-official/clair-client