Hey everybody welcome to the next video.
We're gonna be talking about zero days in this video.
Now what are zero days.
I've mentioned it in previous videos.
However a zero day is a new or previously unknown exploit for a system or a service of some kind.
Now as a quick thing I want to note before I go any further if zero days are found by you or somebody
that you're associated with they should be disclosed in a professional fashion such as you contact the
company discreetly or the owner of the service or the web application.
You tell them what the issue is you give them 60 days give or take 30 to 60 days sometimes 90 days to
fix the problem and for them to release the patch and the accreditation to you for finding said issue.
Some companies have a bug bounty program where you can submit it to them directly and they will pay
you based on how relevant the actual issue was.
So keep in mind doing this in a professional fashion is a good way to keep your reputation up in the
security community rather than just throwing them out to the world because if you find out something
very dangerous such as a remote code execution on a fully patched latest version of Windows or Linux
for that matter you're going to run into serious backlash because somebody is going to grab that turn
it into malware and it's just going to wreak havoc really quickly.
So it's important to keep keep that professionalism at a high point when especially when it comes to
something that's sensitive.
So don't just release them into the wild.
Now there are a few ways to find and find zero days.
Now we're going to go over some of these briefly.
We're not going to look into actually finding zero days in this course we'll have future courses that
I'll be creating or they might already be there depending on when you're watching this on fuzzing a
service which is one of the ways that it's normally found.
So we'll go over finding zero days that way in its own course.
But what I want to point out is that zero days are not just memory based exploits like buzzer or buffer
overflow or SDH exploits sometimes it can be considered a zero day if there's a mis configuration in
the web application by default as an example that causes you to just be able to access the machine that
is definitely a zero day issue.
Again memory vulnerability is a zero day and then denial of service by crashing an app.
Sometimes this is based on memory sometimes the application doesn't know how to handle certain input
that you gave it and it just gives up so crashing a service is still considered a zero day not as devastating
depending on the service and finding zero days is buzzing the application which is sending a different
inputs in certain different ways to try to see how it reacts normally this is done with a father and
manually looking at the service.
So as I talked about before you just send it random stuff large character sets you send it something
is not expecting it it's expecting an integer you give it a string or vice versa.
So you play with it manually.
And the third way and the easiest way is to perform a code audit of the source code itself.
So taking open source stuffs it's pretty easy to find a zero day when you're looking at it at the source
level.
You just have to understand how the code is written and where stuff can be abused which comes in with
some developer experience that you'll probably want or experience looking at code audits.
It is the easiest way but it's also difficult in its own right.
So every every way that you find a zero day has its own challenges has its own requirements.
So fuzzing is a skill set on its own manually prodding a service regardless of whether it's local or
remote depending on the service has its own skill set and then code audit has its own skill set as well.
So these are the general ways that people find zero days.
So I just want to keep that on your radar.
Again this course is going to go over finding them per say but we're going to just know that when as
a red team or when something comes out and we see and we notice it on Twitter or on a news feed or whatever
we want to jump on it pretty quickly to understand how it works.
So I just want you to be familiar with what the concept of zero days.