**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))
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.
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.