FTN Judo - Nachrichten: Mai 2023

ASIS CTF Quals 2015 - Sawthis Writeup - Srand Remote Prediction

The remote service ask for a name, if you send more than 64 bytes, a memory leak happens.
The buffer next to the name's is the first random value used to init the srand()

If we get this value, and set our local srand([leaked] ^ [luckyNumber]) we will be able to predict the following randoms and win the game, but we have to see few details more ;)

The function used to read the input until the byte \n appears, but also up to 64 bytes, if we trigger this second condition there is not 0x00 and the print shows the random buffer :)

The nickname buffer:

The seed buffer:

So here it is clear, but let's see that the random values are computed with several gpu instructions which are decompiled incorrectly:

We tried to predict the random and aply the gpu divisions without luck :(

There was a missing detail in this predcitor, but there are always other creative ways to do the things.
We use the local software as a predictor, we inject the leaked seed on the local binary of the remote server and got a perfect syncronization, predicting the remote random values:

The process is a bit ugly becouse we combined automated process of leak exctraction and socket interactive mode, with the manual gdb macro.

The macro:

Related word

FOOTPRITING AND INFORMATION GATHERING USED IN HACKING

WHAT IS FOOTPRITING AND INFORMATION GATHERING IN HACKING?

Footpriting is the technique used for gathering information about computer systems and the entities they belongs too.
To get this information, a hacker might use various tools and technologies.

Basically it is the first step where hacker gather as much information as possible to find the way for cracking the whole system or target or atleast decide what types of attacks will be more suitable for the target.

Footpriting can be both passive and active.

Reviewing a company's website is an example of passive footprinting,
whereas attempting to gain access to sensititve information through social engineering is an example of active information gathering.

During this phase hacking, a hacker can collect the following information>- Domain name
-IP Addresses
-Namespaces
-Employee information
-Phone numbers
-E-mails
Job information

Tip-You can use http://www.whois.com/ website to get detailed information about a domain name information including its owner,its registrar, date of registration, expiry, name servers owner's contact information etc.

Use of Footprinting & Information Gathering in People Searching-
Now a days its very easy to find anyone with his/her full name in social media sites like Facebook, Instragram,Twitter,Linkdedin to gather information about date of birth,birthplace, real photos, education detail, hobbies, relationship status etc.

There are several sites like PIPL,PeekYou, Transport Sites such as mptransport,uptransport etc and Job placement Sites such as Shine.com,Naukari.com , Monster.com etc which are very useful for hacker to collect information about anyone.
Hacker collect the information about you from your Resume which you uploaded on job placement site for seeking a job as well as hacker collect the information from your vehicle number also from transport sites to know about the owner of vehicle, adderess etc then after they make plan how to attack on victim to earn money after know about him/her from collecting information.

INFORMATION GATHERING-It is the process of collecting the information from different places about any individual company,organization, server, ip address or person.
Most of the hacker spend his time in this process.

Information gathering plays a vital role for both investigating and attacking purposes.This is one of the best way to collect victim data and find the vulnerability and loopholes to get unauthorized modifications,deletion and unauthorized access.