web application security Archives - Page 6 of 9

capture the flag, hacking, owasp, web application security

PicoCTF 2017 – My First SQL

June 29, 2017March 3, 2021 thefluffy007

Another day, another challenge.

Today’s blog post we will be solving the challenge, “My First SQL” from the PicoCTF.

Let’s get started.

Going to the challenge we see:

OK… we need to access a website, but we do not have the password. Let’s see what the hints give us.

Clicking the website link we see:

Doing a right click, view page source we see:

We do not see anything useful. We have a form that is looking for a username and password.

Going back to the hints, let’s do a Google search of SQL Injection.

After doing the search we have a link, that specifies how to do a SQL injection to do login bypass.

Let’s do it.

Going back to the website, we see that we have a username and password.

Let’s try using a username of “admin”

and a password of ” ‘ OR ‘1’=’1′ ”

Pressing login we get:

We found the flag, and acquired 50 points!

capture the flag, hacking, web application security

PicoCTF 2017 – Master Challenge – Lazy Dev

June 27, 2017March 3, 2021 thefluffy007

Another day, another challenge.

Today’s blog post, we’re going to solve the master challenge of level one of the PicoCTF challenge called, “Lazy Dev”.

Let’s get started.

Clicking on the challenge we see the following:

Hmm… we need to log into the application even though the login logic has not been implemented.

Clicking on the link we see:

Going back to the challenge and look at the hints we see:

OK. The hints state maybe we need to interact with JavaScript.

Going back to the website and doing a right click, view page source we see:

We see there’s a input box for password that is calling the process_password function. Where is this function coming from? Maybe it’s coming from line 10 that has a javascript source file named client.

Clicking this file (client.js) we see:

Looking at the first function validate(pword) we notice it’s not implemented. It’s always going to return false, with the comment – todo: implement me

Going back to the hints we remember that we need to access the JavaScript directly. We can do this by viewing the developers tools.

Let’s view the development tools by pressing F12 on our keyboard, and then pressing F5 to refresh the page.

When we do this, we see:

Clicking on the sources we see the files that were loaded from the web page.

Looking at line 26 we see that we’re calling the make_ajax_req. Inside this function we see in line 15 checks the state change. If the state changes we’ll get the password.

How can we change the state when the login has not been implemented?

Let’s see if we can call the make_ajax_req function directly from the console.

First, let’s add a break point to line 15 in the make_ajax_req function.

Next we’ll add the following to the console:

Pressing Enter we go to the break point.

We’re accessing the JavaScript directly!

Stepping through the code multiple time we noticed that we execute line 15 of the make_ajax_req function.

Once it’s done we see there’s text that’s inputted inside the browser.

Looking at the browser we see:

We have the flag!!

Entering the flag we’ve acquired 50 points, and unlocked level 2!

capture the flag, hacking, web application security

PicoCTF 2017 – WorldChat

June 19, 2017March 3, 2021 thefluffy007

Another day, another challenge…

In today’s blog post we will be solving the “WorldChat” challenge from the PicoCTF.

Let’s get started!

Going to the challenge we see:

OK so we need to find the flag inside of the WorldChat app. According to the description when connecting to this app there will be many people on the app besides us.

Let’s look at the hints to see if it will help us.

We need to us the nc command (we’ve used this in another challenge) and use the grep command to filter output.

Let’s try it.

Connecting to the server we see a bunch of chats from different people. I pressed Ctrl + C to stop it.

Let’s use the hints and use the grep command with the “|” (pipe) command.

Press Ctrl + C to end the chat.

I have only captured screenshots of output that has the flag. Entering the flag into the input box we acquired 30 points.

capture the flag, hacking, web application security

PicoCTF 2017 – What Is Web

June 18, 2017March 3, 2021 thefluffy007

Another day, another challenge.

In today’s blog post we are solving the challenge, “What Is Web” from the PicoCTF challenge.

Let’s start!

Clicking on the challenge we see:

OK, so we need to find out how to use HTML.

Looking at the hints we see:

Clicking on the website we see:

Doing a right click, view source we see:

At the bottom of the screen in the green letters (which are comments that are not displayed in the browser) show that we have the first part of the flag.

Now we need to find the second and third part of the flag.

Looking back at the page source we see two different files that are referenced: hacker.css and script.js

Let’s look at hacker.css first and see what’s there.

Going to that file we see the second part of the flag at the top of the browser:

Now let’s look at the script.js file and see if we can find the final part of the flag…

Going to the script.js file we see:

We now have the three parts of the flag!

Combining the parts together and submitting the flag, we’ve acquired 20 points!

capture the flag, hacking, web application security

PicoCTF 2017 – Internet Kitties

June 14, 2017March 3, 2021 thefluffy007

Another day, another challenge…

Today’s blog post we will solve a problem in the PicoCTF challenge.

Let’s start!

After logging into the CTF, and clicking on the “Internet Kitties” challenge we’re presented with the following:

Reading the description, really doesn’t give a lot of clues. Clicking on the hints tab we see:

OK, so we need to use the netcat command. On the right side of the panel we’re presented with a command prompt. After logging in we have the following:

Executing the help command (nc -h) in the command prompt we see:

The first line we see is how to connect to a server. Maybe we can use this to solve the challenge?

Looking at the challenge again we have the host name and port.

Let’s try it and see what we get:

We found the flag! Entering the flag we scored 10 points!

capture the flag, hacking, web application security

PicoCTF 2017 a Brief Introduction

June 14, 2017March 3, 2021 thefluffy007

Another day, another challenge…

Today’s blog post will discuss another CTF – PicoCTF.

The target audience for PicoCTF is a computer security game that is aimed at middle school and high school students, but anyone can join and play.

Topics explored are: forensics, cryptography, reverse engineering, web exploitation, binary exploitation, and miscellaneous challenges.

To learn more, go here.

Happy hacking!

capture the flag, hacking, web application security

InfoSec Institute CTF Challenge #14

June 10, 2017March 3, 2021 thefluffy007

Another day, another challenge.

Today’s challenge comes from the InfoSec Institute CTF program.

Going to the following link we see the following:

Doing a right click, view page source we see the following:

Hmm… there’s a file, titled level14 inside the misc folder. Let’s go that file and see what’s there…

Going to the file we see the following:

Hmm… it looks like we have a SQL dump that’s showing us all the tables and values inside of a php application.

Scrolling down we see something that looks interesting, and strange…

Could this be some type of encoding? Possibly hexadecimal encoding?

First, we don’t need the double forward slash, we just need one. Removing the extra slashes we get the following:

Using a Hex to ASCII converter here, we get:

We found the flag – infosec_flagis_whatsorceryisthis

Lessons learned:

Our trick still works! We were able to find valuable information when looking at the page source. Going to the file listed we noticed it was a dump of SQL tables. Looking through the tables we noticed suspicious output, which we guessed was some type of encoding. Using information we learned from a previous challenge we were able to deduce that the encoding was hexadecimal encoding. From there we were able to find the flag.

capture the flag, hacking, web application security

InfoSec Institute CTF #13

June 10, 2017March 3, 2021 thefluffy007

Another day, another challenge…

Today’s challenge is from the InfoSec Institute.

Going to the following link, we see the following:

Doing a right click, view page source we see the following:

So from the hint we’re looking for a back-up file.

Since this is on a Linux box, let’s see what what the naming conventions are for backup files.

Let’s see if there’s a backup folder.

That led us to a dead-end.

Let’s try adding .old at the end of the file.

Adding the “.old” at the end of the URL and pressing enter we get the following:

Hmm… this looks like another file. Let’s open it.

Opening the file in a text editor we get the following:

Looking at the file we see the the first paragraph, which matches our first screenshot.

Next we see commented out code, that is asking us to download a mysterious file, “iamadecoy”.

Let’s navigate to this file and see what we find.

After the file downloads, we try to open it.

Hmm… that’s weird when clicking on the file a prompt is shown asking what type of file this is.

Since we don’t know what type of file it is, let’s go to this site here, to find out.

After uploading our file we determine that is a pcap file.

We’re going to need Wireshark for this one…
Opening Wireshark, and opening our file we’re presented with the following:

The beginning of the file is DNS queries that are rejected we can ignore that.

Searching through the file we notice some HTTP requests that are getting files, in particular – HoneyPy.png

Going to packet 633

We can reconstruct this exchange.

Going to File –> Export Objects –> HTTP

We get the following:

Our file is highlighted in the above screenshot, so let’s click Save.

Opening the file we get our flag!

Lessons learned:

Use the hints that are provided! We knew that the file we were looking for was a backup. After playing around with the filenames we discovered that the file we were looking for ended in an “.old”. Once we opened the file we noticed there was another file “imadecoy”. After downloading that file and trying to open it our operating system was confused on the file type. Uploading our file to the above link we determined that the file had a pcap (packet capture) extension, and we would need to use Wireshark.

Opening Wireshark, we determined that the file we needed was inside of an HTTP packet. Reconstructing the packet we were able to download the file we needed. After opening that file we received our flag. This challenge was a multi-step process. It’s very important to pay attention to detail.

capture the flag, hacking, web application security

InfoSec Institute Challenge #12

June 8, 2017March 3, 2021 thefluffy007

Another day, another challenge.

Today’s challenge is coming from the InfoSec Institute.

Going to the following link we see the following:

Doing a right click, view page source we see the following:

We noticed there’s an extra CSS (Cascading Style Sheets). Let’s see what’s in this file.

Going to the file we see the following:

Hmm… this looks interesting. Knowing a thing or two about CSS, the colors are represented in hex (hexadecimal, base 16) form. More can be found here.

I’m thinking this is the actual flag, but it’s just encoded.

Using out knowledge from other challenges, let’s try base64 decoding, since it has worked before.

Going to the link here, and typing in the encoding we get the following:

Our decoding wasn’t successful. This encoding is not base64.

Going back to the challenge, we know that CSS uses hexadecimal to represent colors.

Maybe the encoding is in hexadecimal form.

Going to Google and typing in “converting hexadecimal to text” we get the following link.

Putting our encoding in the text box and changing the decoding to “hexadecimal to text” we get the following:

We found the flag!

Lessons learned:

Attention to detail! We noticed that there was another file when we did the right click, view page source. Going to that page we noticed that there was encoding. We first tried base64 which did not work. Going back to the drawboard on how CSS works, we know the colors are represented in hexadecimal. Doing a Google search of hexadecimal to text we were able to find the flag.

capture the flag, hacking, web application security

InfoSec Institute CTF Challenge #11

June 7, 2017March 3, 2021 thefluffy007

Another day, another challenge.

Today’s challenge is from the InfoSec Institute CTF.

Going to the following LINK we see:

Doing our favorite trick of right click, view page source we see the following:

We see an image of “php-logo-virus.jpg” hmm… what happens when we click this file?

We see the following:

Looks like a simple file… looks can be deceiving.

Just going from the title of the file, there’s something in this file that we’re not seeing.

Let’s use our trick from the last challenge of using strings to see if this is a true file.

Using the strings command inside our cygwin terminal we see the following:

Hmm… we see the beginning part of the flag. The last looks like encoding.

Let’s try to decode it.

One of the encoding we’ve seen in the challenges have been base64 encoding, so let’s use that to see if we can decode the message.

Going to this link, and typing in the encoding we see the following:

We’re presented with a link. Going to that link we see the following:

Combining the this with the beginning of the flag, we get infosec_flagis_powerslide!

Lessons learned:

Most of these challenges build on top of each. We still used our tried and true right click, view page source to see if there are any nuggets that were not shown on the page. We noticed there was a file. Looking at the name, we determined that there was more than what met the eye. Using another command we learned – strings we were able to see that the flag was embedded in picture, but it was encoded. Using previous knowledge, we noticed that previous challenges used base64 encoding so we used that (base64) to see if we can decode the text. After decoding we went to the link and used the image to complete the flag.