# 43 - Pentesting WHOIS

## Basic Information

**WHOIS** (pronounced as the phrase "who is") is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block or an autonomous system, but is also used for a wider range of other information. (From [here](https://en.wikipedia.org/wiki/WHOIS))

**Default port:** 43

```
PORT   STATE  SERVICE
43/tcp open   whois?
```

## Enumerate

Get all the information that a whois service has about a domain:

```bash
whois -h <HOST> -p <PORT> "domain.tld"
echo "domain.ltd" | nc -vn <HOST> <PORT>
```

Notice than sometimes when requesting for some information to a WHOIS service the database being used appears in the response:

![](https://4153509160-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MaoGr_g3I50alM2whW0%2Fsync%2F787660d151b59fb222178c59398c5d105ff4ff00.png?generation=1622227479350941\&alt=media)

Also, the WHOIS service always needs to use a **database** to store and extract the information. So, a possible **SQLInjection** could be present when **querying** the database from some information provided by the user. For example doing: `whois -h 10.10.10.155 -p 43 "a') or 1=1#"` you could be able to **extract all** the **information** saved in the database.

## Shodan

* `port:43 whois`