Subdomain takeover on *.apachecn.org

## Summary

The domain **apachecn.org.io** has a subdomain wildcard CNAME record pointing to **apachecn.github.io**. This allows an attacker to use any subdomain he wants on apachecn.org with Github pages.

## Security issue

An attacker could create it's own repository and configure it to use any subdomain he wants, allowing him to serve it's own content.

## POC

I have made [a POC](http://what-i-want.apachecn.org/).


## Remediation

Remove the wildcard CNAME record for apachecn.org.

## Impact

This issue make it possible for an attacker to carry out several type of attacks like XSS, phishing campaign or session hijacking.

Comienza revisando la configuración CNAME comodín descrita en el issue y la prueba de concepto enlazada en what-i-want.apachecn.org. Confirma si apachecn.org sigue dirigiendo subdominios arbitrarios a apachecn.github.io; se considera terminado cuando se elimina el registro CNAME comodín y el subdominio de la prueba de concepto ya no sirve contenido controlado por un atacante.

Escrito por el modelo de indexación a partir del texto del issue.