On Pins and Needles

Clotilde

This story is about a bug generated by g++ and clang compilers (at least)
The condition_variables is a feature on the standard library of c++ (libstdc++), when its compiled statically a weird asm code is generated.

Any example on the link below will crash if its compiled statically:
https://en.cppreference.com/w/cpp/thread/condition_variable

In this case the condition_variable.wait() crashed, but this happens with other methods, a simple way to trigger it:

If this program is compiled dynamically the crash doesn't occur:

Looking the dissasembly there is a surprise created by the compiler:

Compilers:
g++ 9.2.1+20200130-2
clang++ v9

Both compilers are generating the "call 0x00"

If we check this call in a dynamic compiled:

The implementation of condition_variable in github:
https://github.com/gcc-mirror/gcc/blob/b7c9bd36eaacac42631b882dc67a6f0db94de21c/libstdc%2B%2B-v3/include/std/condition_variable

The compilers can't copile well this code in static, and same happens on other condition_variable methods.
I would say the _lock is being assembled improperly in static, is not exacly a null pointer derreference but the effects are the same, executing code at address 0x00 which on linux is a crash on most of cases.

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Clotilde

Are you tired of reading endless news stories about ethical hacking and not really knowing what that means? Let's change that!

This Post is for the people that:

Have No Experience With Cybersecurity (Ethical Hacking)
Have Limited Experience.
Those That Just Can't Get A Break

OK, let's dive into the post and suggest some ways that you can get ahead in Cybersecurity.

I receive many messages on how to become a hacker. "I'm a beginner in hacking, how should I start?" or "I want to be able to hack my friend's Facebook account" are some of the more frequent queries. Hacking is a skill. And you must remember that if you want to learn hacking solely for the fun of hacking into your friend's Facebook account or email, things will not work out for you. You should decide to learn hacking because of your fascination for technology and your desire to be an expert in computer systems. Its time to change the color of your hat 😀

I've had my good share of Hats. Black, white or sometimes a blackish shade of grey. The darker it gets, the more fun you have.

If you have no experience don't worry. We ALL had to start somewhere, and we ALL needed help to get where we are today. No one is an island and no one is born with all the necessary skills. Period.OK, so you have zero experience and limited skills…my advice in this instance is that you teach yourself some absolute fundamentals.

Let's get this party started.

What is hacking?

Hacking is identifying weakness and vulnerabilities of some system and gaining access with it.

Hacker gets unauthorized access by targeting system while ethical hacker have an official permission in a lawful and legitimate manner to assess the security posture of a target system(s)

There's some types of hackers, a bit of "terminology".
White hat — ethical hacker.
Black hat — classical hacker, get unauthorized access.
Grey hat — person who gets unauthorized access but reveals the weaknesses to the company.
Script kiddie — person with no technical skills just used pre-made tools.
Hacktivist — person who hacks for some idea and leaves some messages. For example strike against copyright.

Skills required to become ethical hacker.

Curosity anf exploration
Operating System
Fundamentals of Networking

*Note this sites

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Clotilde

You might have harvested many things upto now but what we are going to harvest today is something bad :)

Requirements:

A Linux box (I'm using Kali Linux)
theharvester program (already available in Kali Linux)

So what does theharvester harvest? Well it harvests email addresses. theharvester is an Information gathering tool. If you want a list of emails to spam you can get that easily from theharvester tool and go on Spamming (I'm joking its illegal). It's a security tool that helps you in pentesting an organization (as always it can be used for evil as well). You can gather emails from an organization and look for potential victims to attack or use brute-force techniques to get their passwords or Social Engineer them into doing something that will let you compromise some or all systems in the organization. Uhh there are so many things that you can do when you have access to someone's email address.

OK stop talking and start doing.

Fire up a terminal in your kali box and type this command:

theharvester -d hotmail.com -l 50 -b google

In a small amount of time you'll see your terminal flooded with 200 hotmail.com email address. What does this command mean?

theharvester is the tool name that we are using
-d <domain_name> specifies the domain (or website) who's email addresses we're looking for, in our case it was hotmail.com
-l <number> specifies the number of results that we want in the output, I limited it to 50
-b <source> specifies the source on which to look for email addresses, I specified google as the source

Besides google we can specify any of the follow as source:
google, googleCSE, bing, bingapi, pgp, linkedin, google-profiles, people123, jigsaw, twitter, googleplus, all
Here the last entry all means look in every available source.

Let's say you wanted to look in every available source they you should specify the following command:

theharvester -d hotmail.com -b all

-f is another great flag which can be utilized to save the output in case we want to SPAM them later (just kidding) or for other reasons (I'm thinking positive). -f flag saves the result in html or xml format. Let's do just that:

theharvester -d gmail.com -l 50 -b google -f emailaddresses.html

here -f flag is followed by the location where we want to store the file and the name of file, in our case we stored it in our pwd (present working directory) with the name emailaddresses.html.

Above picture shows an html output generated by harvester.

That's it for this tutorial hope to see you next time!

On Pins and Needles

Sunday, August 30, 2020

C++ Std::Condition_Variable Null Pointer Derreference

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Saturday, August 29, 2020

Vulnerable-AD - Create A Vulnerable Active Directory That'S Allowing You To Test Most Of Active Directory Attacks In Local Lab

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How To Start | How To Become An Ethical Hacker

Theharvester: Email Harvesting Throughout Year

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