About Graeme Robinson

My job is as a software tester with a bit of support, but I also know quite a bit about hardware because that's how I got into computers. I also like to climb rock in my spare time. This blog will mostly document my quest to get into the information security field. Probably with emphasis on webapp security.

New alternate emoji domain

This is not really security related, but it’s a bit of fun so I wrote a quick post.

I had heard that emoji domains are available from select TLDs, so I decided to buy one! I am now the proud owner of 💻☠.ws, which mirrors this site.

Now, if you go to grobinson.me and your browser supports emoji domains without displaying the punycode translation (xn--h4h3030o.ws) in the address bar, you will be redirected to the same page on 💻☠.ws thanks to this little piece of javascript.

Check your address bar now. You may already using the emoji domain without even knowing.

nc.exe v1.10 NT crashes when -e used and <323 bytes sent in a line

I’m currently working through the PWK course from offensive-security, hoping to get my OSCP certification. While following the course materials, I’ve got to a section that talks about methods of transferring binary files after you have a shell on a remote system.

One of the methods suggested is converting the file to text using exe2bat.exe to convert the file into a series of echo commands with redirection to a file that can be copy/pasted into the shell and finally running debug.exe to convert the file back into an exe. It’s a pretty well known method, detailed instructions can be found easily with google.

I hit a problem when working through this though… I created a bind shell using nc.exe (v1.10 NT) and when i connected to this and pasted in the lines from the bat file created by exe2bat.exe, the nc.exe process would crash. It turned out to be crashing when it got the 3rd line from the bat file. I thought this was strange, so I contacted offensive-security support and they confirmed my findings, but weren’t sure why and suggested I used a different method to get a remote shell, e.g. using msfvenom.

I have done some testing myself, and wrote a python script that tells me what it received and how long it was so that I could see in more detail what was going on. The script is:

#!/usr/bin/env python3
import sys
print('pypipe.py v0.1')
print('--------------', flush=True)
for idx, line in enumerate(sys.stdin):
    line = line.strip()
    print('# Received line {}. Length (bytes):{}'.format(

Binding this to port 80 on windows with

nc -nvlp 80 -e "py pypipe.py"

and then connecting with netcat on my other system makes any input get reported back to the remote system line by line, and i can see that the problem happens when a long line is sent. I could also tell that it accepted a line with 323 characters, but when i sent 324, it crashed.

I suspect I’m seeing the bug mentioned here and here.

So I’ve learned that I can’t use that version of nc.exe to send binary files that have been converted into long text strings. Different versions of nc probably don’t have this issue.

While this is a problem because it’s an exploitable bug, this is not much of a problem for transferring binary files because in real world secenarios because there won’t be nc.exe on the system unless I’ve already found a way of getting a binary file onto the system, but it’s something that did trip me up for a few hours while doing the PWK course.

Hack the Box

I recently came across Hack The Box and have been having fun pwning some of those machines using the techniques that I have learned in the free Metasploit Unleashed course. Metasploit really is a great tool, and even though I could have got some “user owns” without it, I found that once I had learned how to use things like msfvenom, it saved me having to write some of my own trivial scripts, which saved me time.

I’ve currently got 3 “System Owns” and 4 “User Owns”, which puts me on “Script Kiddie” status. I’m hoping to get a few more and move to a better status fairly quickly, if I can find the time to play around some more.

I especially like the way you have to hack the invite before you can gain access to any machines. It was probably the easiest part of any of the challenges I have attempted, but that might be because I’m pretty familiar with web technologies.

If you haven’t tried it out, I would encourage you to do so. The website is very polished, and there are quite a lot of machines to attack 🙂

B-Sides London 2017

I took a day off from work on Wednesday last week to go to B-Sides London, and had probably the best day this year! There were so many interesting talks and loads of great people to chat to (and potential job opportunities). I even won a wristband which game me access to the MWR sponsored afterparty with free drinks 🙂

The most entertaining talk by far was by @info_dox titled “A look at TR-06FAIL and other CPE Configuration Disasters”. Darren showed up with a pint in his hand and proceeded to tell us all about the problems with the Broadband Forum‘s protocols and their various implementations.

I came away with a bit of swag too, 3 T-Shirts, and a signed copy of “Breaking Into Information Security by Andy Gill (which reminds me, I must get in contact with him for the digital copy he promised me).

I’d like to say a big thank you to all the volunteers who made it such a great event. Hopefully in the future, I’ll be able to give something back by helping out at one of these events, or something similar.

I’ve signed up to the Penetration testing with Kali Linux Course (OSCP)

Last week I signed up for the PWK course from Offensive Security starting in mid June with the intentions of getting the OSCP certification. I booked 60 days of lab access; I hope that’s enough, but if I don’t manage to find enough free time in those 60 days, I should be able to book some time off work towards the end. Failing that, I can always buy more time in the labs if I really need it.

I’m interested to see how I’ll handle the 24 hour exam at the end. Sounds like a fun challenge, which I suppose if what the whole point is (as well as proving skills).

In the weeks before that course starts, I’m working my way through the Metasploit Unleashed course, also by Offensive Security. Looks like a great tool, from what I’ve learned about it so far.

Am I officially a white hat hacker now!?

A while ago, while developing a geocaching app for pebble smartwatches called “Watch Caching”, I noticed a bug that could have security implications, so I reported it to Pebble using the whitehat guidelines set out by theme

It took them a while, but they eventually got back to me and agreed that it was a security vulnerability and wanted to offer me a significant financial reward, as well as put me in the Pebble White Hat Hall of Fame

This also took a while to come to fruition, but they did hold true to their word and sent me the money, followed a few days later by my name being added to the Pebble White Hat Hall of Fame!

Developing and debugging my own apps on JailBroken iOS8.1 using XCode 6.1 without paying apple

A while back I used an app called JailCoder to enable me to run and debug my own apps on my jailbroken iPhone 5S without having to pay Apple for a full developer account. I’m still learning iOS development and I have nothing I want to submit to the app store, so I’m reluctant to pay the £100 that Apple wants to enable me to run my own code on my own device.

Given that XCode is free, and that £100 per year would gives me the ability to sell apps through the app store, I think it’s a bargain if you are actually planning to distribute apps, but for me just learning it seems a bit steep.

There don’t seem to be many tutorials out there telling you how to do this for iOS8.1 and XCode 6.1 (they are all a bit outdated), but this is what worked for me:

  1. On your Jailbroken device install AppSync Unified 5.2-1 (or later) from AngelXWind’s repo. Don’t use any other AppSync, and if you have others, be sure to remove them.
  2. Open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/SDKSettings.plist and change AD_HOC_CODE_SIGNING_ALLOWED to YES. You may need to duplicate it to the desktop, change it, save it, then drag and drop back into the original folder because OS X let you edit the file in place.
  3. If XCode was running, restart XCode.
  4. Change your Project and Target settings to “Ad Hoc Code Sign” in Build Settings
  5. Tell XCode to run app on iPhone. At this point XCode will put app on your iDevice, but can’t debug because it can’t attach to the process. The app will start then close immediately. You can now manually start the app on the phone now though.
  6. To enable debugging: In your project select File>New File Property List and create a file called “Entitlements.plist”. Add “Can be debugged” or “get-task-allow” (both do the same thing) and set the value to YES.
  7. Now change your Project and Target Code Signing Entitlements (In Build Settings) to “Entitlements.plist” (you have to type it in).

Now XCode can run and debug the app. Good luck

Note that some poeple have issues because they have other appsyncs installed. Remove all other appsyncs and install AppSync Unified from http://cydia.angelxwind.net/ (you’ll have to add this repo to cydia)

Thanks to Karen and Linus for developing AppSync Unified.

This subreddit may be helpful

I have a Raspberry PI on the way

I ordered a Raspberry PI yesterday.

I used to have a server running at home which served files, recorded tv, provided VPN, but I moved into a small flat, and there’s not much room for a server, not that my fiancée would be happy with anyway!

The PI will give me a little server back again for the duration that I’m in this flat. I’m also looking at playing with xbmc and perhaps some pvr capabilities on it. Should be fun!

My first pentest on a friend’s network

Someone I have know for a while was aware of my growing interest in information security and I had warned them a while ago that their network was probably vulnerable to attack because I had seen some web services that were not password protected running out of their home public IP address.

I saw them over the Christmas/new year period and they gave me permission to try and penetrate their network, specifically they challenged me to change the root password on their unRAID server.

I started off by firing up my Backtrack 5r3 VM and updating everything before registering Nessus and performing a scan of his public IP address.

Nessus didn’t find anything that was listed as critical, but it did show me that we had ssh running on port 22 and it also showed me all other ports that were open and had web servers running on them. I checked them all out and I found on various ports; the default Lion server webpage, SABNZBd, SickBeard, Transmission, and the unRAID server.

The website served by the unRAID server was asking for a username and password using basic access authentication. That was no use so I started looking into the other services. Not only were the operating interfaces unsecured, but their configuration sections were also open to anyone. I saw that SABNZBd was running as “admin” and that it had an option of running scripts when a download had completed. The method was to point SABNZBd to a folder containing scripts, start a download and then choose what script to run on completion. I knew I could download a file using SABNZBd or Transmission to any directory that the admin user had write permissions to, but I didn’t know at this stage how to make it executable.

I saw in SABNZBd’s preferences that I could specify the permissions (in octal format) of files and folders that were downloaded, so I ran SABNZBd on my machine, created a binary post on a newsgroup containing a script that was basically a reverse shell and tested a download to my machine with SABNZBd set to mark everything at 777. It created a folder with 777 permissions, but the file was only 555. Presumably this was for security reasons – damn!

At this point I was wishing that his machine was running Windows not OSX because SABNZBd on Windows only requires that a scripts file extension is in the PATHEXT environment variable. That would have been much easier than getting a file marked as executable.

I had to find another way of making an executable script on that machine. How could I get that machine to run my commands without having an executable script set… The web server or course. I created my single line PHP shell again (mentioned in a previous post) and set Transmission to download files to the Lion web server default folder, created a torrent containing my php script and downloaded the torrent to the server using transmission. I tested it, with the command whoami, and it worked. I was in, but I was only the user _www.

What could I do as _www? Not much, but I was able to create a reverse shell using netcat and take a look around the system. I couldn’t access admin’s files yet, but of course I could write to /tmp. If I could write to /tmp, I could create a script and mark it as executable by everyone. Then I could get SABNZBd to run it! I started thinking about making a script that would create a reverse shell, then it dawned on me: create a public/private key pair and add it to /Users/admin/.ssh/authorized_keys.

I uploaded my public key using my php shell script, and then created an executable script in /tmp that appended my key to authorized_keys.

I started a new SABNZBd download (I decided to just download something that was small, free and released under the CC license) so as no to upset anyone. Obviously I now set my script to run. All went well and I could now ssh into the machine as the admin user without a password.

At this point I cleaned up everything I had downloaded and just left my key in place so I could log in. I took a look around, but I couldn’t see anything to do with the unRAID server, so I thought I should report how far I had got.

They were surprised, and while I didn’t get into the unRAID server, I had gotten a lot further than they thought anyone would be able to. As a result of this, they have since enabled logins on all their web services and removed my public key, but they still do have some vulnerabilities, like ssh running on a default port and allowing password authentication (ripe for brute forcing). They are a lot safer than they were, but it may well be worth me going back and having another go at some point in the future.

A lot of the methods that I have used in this test were inspired by the challenges I have been working through in hackthissite.org and exploit-excercises.com and I’m very grateful to them for making the challenges.

I’m tempted to try and create a VM with this vulnerable setup and release it. I would have to check the licences, but I think most of it could be done using open source solutions (linux, apache, sabnzbd, transmission)

Match.com just sent me an email containing my password in plain text!

A few weeks ago, when I was going through all my online accounts and making the passwords more secure and unique I logged in to Match.com and deactivated my account. I didn’t delete it, just made it dormant. I did this because I found my Fiancée over 3 years ago (via Match.com) so there was no reason to still have an active account. I didn’t want to delete the account because it had some of our earliest messages to each other saved.

Anyway, I checked my emails today and noticed that I had one from them encouraging me to re-activate my account. What was more concerning was that the email contained my password in plain text! Here is a screenshot of the email:

Screen Shot 2012-12-31 at 10.13.27

I was about to submit them to plaintextoffenders.com but I did a search before and found that they were already added to the list 15 months ago, so I left a comment on the plaintextoffenders listing and decided to send a message to Match.com. The message was:

On the 20th of December 2012 I received an email encouraging me to reactivate my account. What concerns me is that in the body of the email was my password, in plain text! Firstly you should not be storing my password in plain text, and secondly (if you insist on storing passwords as plain text) you should not be sending it to me over something as insecure as email, especially if I didn’t request it!

I was about to submit match.com to http://plaintextoffenders.com, but when I searched, I saw that it was already submitted some 15 months ago. See http://plaintextoffenders.com/post/9744438766/match-com-dating-site-very-soon-after-i-got-this.

For a brief overview of why storing passwords in plain text is bad, you can start reading here: http://plaintextoffenders.com/about/

Please bear in mind that while you are now being shamed by plaintextoffenders.com, if you decide to fix the security flaw, your site would be moved to a different section of the site where you would be praised for admitting the fault and fixing it. See http://plaintextoffenders.com/reformed

I am in no way affiliated with plaintextoffenders.com, but I do support what they are trying to do and I would like to know if you are in the process of fixing, or plan to fix this security flaw in the near future?

Please reply to <email address removed>

I will update this post if/when I get a reply, but in the meantime I would recommend against joining Match.com and deleting any accounts you might have with them until they act a bit more responsibly.

Update: I got this email back from Match.com:

Thank you for contacting us at match.com.

We understand that you received an email from us on the 20th December 2012 with your password in plain text which you feel is a serious compromise of security.

We are really sorry about this error and I have forwarded your issue to our site developers to look into.

We hope you have found this information useful and please feel free to get in touch if there is anything further we can help you with. For answers to the most common questions click ‘Help’, available from the foot of any page.

At least they are not dismissing it. I wonder if anything will actually change?