Recently, Apache released Apache httpd 2.4.26. And 2.4.26 fix a lot of issues. You can find the detail in this link. One of the issue is CVE-2017-7659. This article will discuss this issue and show the payload.
After you install Kali Linux, you cannot update it. Because it does not have any upgrade source, we have to add them manually. This article will tell you how to add repositories. If you want to know more information about Kali Linux, you can go to official website.