Hi. I’m Prateek Gianchandani.

Security Researcher. Mountaineer. Diver.

iOS Application Security Part 44 - Bypassing Jailbreak detection using Xcon

In this small article, we will look at a very handful utility named Xconfor bypassing Jailbreak detection. As per the wiki page …

xCon is a collaborative project by n00neimp0rtant and Lunatik that aims to be an all-in-one solution for hooking every known method and function responsible for informing an application of a jailbroken device. At first, the project aimed to patch applications on a per-app basis, but now it uses lower-level hooks to cover any apps that attempt to use the same procedure, even patching apps not explicitly reversed by the developers. Originally an open-source project, it remains closed-source now to discourage App Store developers from working around xCon’s hooks.

A very handful resource for detecting jailbroken devices can be found here. Here is a screenshot from the page. The purpose of Xcon is to make sure all these checks fail.

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iOS Application Security Part 43 - FAT binaries & LLDB usage continued

In this article, we will talk about FAT binaries and see more usage of LLDB.

Fat binaries are single binaries that are compiled for different architectures. They are done so because it is easier to ship a single binary for different architectures. Apple has been changing the architecture in the last three versions of it’s iPhones, armv7, armv7s, and arm64. The good thing is that new iOS devices can run applications compiled for older architectures as well. However it is recommended to upgrade the architecture of the application for enhanced performance.

You can see the architecture for your project by going to the Project in Xcode and looking under Build Settings.


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iOS Application Security Part 42 - LLDB Usage continued

In this article, we will look at some of the most important commands in LLDB to debug applications.

If you have been following this blog series, you would have noticed that we have been using GDB until now for debugging applications, but the support for GDB has been disabled by Apple. Apple has compiled a very useful list of GDB to LLDB commands to get you up to date with debugging via LLDB that can be found here.

We will look at some of the most important commands after hooking into an application. In this case, lets start debugging the Twitter app. So make sure that the Twitter app is running in the foreground on the device and start a listener for the Twitter app.


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iOS Application Security Part 41 - Debugging applications using LLDB

In this article we will learn about the LLDB debugger used by Apple’s Xcode for debugging applications, understand why it is better for security testing, and then learn how to use it to debug iOS applications.

The following excerpt is from Apple’s documentation.

LLDB is Apple’s from the ground up replacement for GDB, developed in close coordination with the LLVM compilers to bring you state-of-the-art debugging with extensive capabilities in flow control and data inspection. Starting with Xcode 5, all new and preexisting development projects are automatically reconfigured to use LLDB. The standard LLDB installation provides you with an extensive set of commands designed to be compatible with familiar GDB commands. In addition to using the standard configuration, you can easily customize LLDB to suit your needs

A good way to start leaning about the LLDB debugger is to watch this video from WWDC 2014.

But the question that remains is, why is LLDB better than GDB ?

To sum it up, there are a few reasons for that.

  • It works well for iOS 8
  • LLDB is much faster, has support for multithread programming, and is scriptable.
  • LLDB understands the dot syntax. You can use something like po self.propertyName or even po instanceVariable to find any value of a property or instance variable while debugging applications.
  • It has plug-in support for functionality and extensions.
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iOS Application Security Part 40 - Testing apps on your Mac

In this article, we will discuss the extent to which you can test applications on your Mac rather than the. This could be useful for many reasons, sometimes you may not have a jailbroken but want to get a POC for a vulnerability. We will discuss what are the things you can and cannot do. To test the application on your system, you will need to have Xcode installed on your system and you will run the applications on the iOS simulator.

Installing ipa files from iTunes on your simulator

Sadly, there is no way you can do that. This is because the iTunes applications are compiled for the ARM platform whereas the applications that run on your simulator are compiled for the x86/x64 platform. So, to test any application properly on your Mac, you must have the source code of the application to run it on the simulator.

In this case, we are going to perform our testing on Damn Vulnerable iOS app

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Damn Vulnerable iOS App solutions free for download

I have decided to give away the solutions for DVIA for free. The reason for this has been too many people coming up with queries for the solutions and i believed giving away the solutions for free would really benefit the infosec community. It has taken me a lot of nights and hard work to create this project and specially the solutions. If you think this project has been useful to you and your organization, please consider making a donation to this project. You can donate to this project and download the solutions for free from here.


Android Application hacking with Insecure Bank Part 4

In this article, we will look at a very handy framework for analysis of android applications named Drozer. Drozer is a very useful tool as it eliminates the need for having seperate tools for performing different security checks in an android application. It has a list of modules that you can use to interact with the application using Android’s Inter-Process communication. Additionally, you can also install exploits and use it to exploit an android device.

The main purpose of this article is to make sure you are familiar with drozer so we can use it in the future articles.

The first thing to do is to install the drozer community edition from this link. You need to install both the drozer installer and the Agent.apk file which is the application that needs to be deployed on the device/emulator and acts as a communicator between the system and the application to be audited.

Once drozer has been installed on your system, install the agent.apk on your device/emulator.


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Android Application hacking with Insecure Bank Part 3

In this article, we will look at attacking components in Android applications, starting with activities. But first, it is essential to understand what Android application components are. Android application components are the essential building blocks of an Android application. The behaviour and interaction between these components is defined in the manifest.xml file in the application. Mainly there are 4 types of components and it is important to understand their purpose and function.

The description of the 4 components given below has been taken from this link.

ActivitiesThey dictate the UI and handle the user interaction to the smartphone screen
ServicesThey handle background processing associated with an application.
Broadcast ReceiversThey handle communication between Android OS and applications.
Content ProvidersThey handle data and database management issues.
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Android Application hacking with Insecure Bank Part 2

In the previous article, we looked at setting up a mobile pentesting platform for Android applications. By now, you must have set up an emulator using genymotion and installed all the android command line tools along with some other additonal tools (drozer, dex2jar, apktool). In this article, we will look at some information gathering techniques. We will see how we can decompile an application to its java source, analyze the signature of the application and many more things.

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iOS Application Security Part 39 – Sensitive information in memory

In this article, we will look at analyzing the memory contents of an iOS application. iOS applications may store sensitive information like passwords, session IDs etc in the memory of the application without releasing them. In some cases, releasing these variables may not be an option. For e.g, it might be required for the application to send an authentication token with every request and hence there has to be a reference to it in the memory somewhere. Even though these variables might be encrypted when stored locally in the application, these variables will be in their unencryped format while the application is running. Hence, analyzing the contents of the memory is an important thing while pentesting an iOS application. If there are some important properties or instance variables that are not required, they should be released from the memory.

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iOS Application Security Part 38 - Attacking apps using Parse (Guest Lecture by Egor Tolstoy)

This is a guest lecture by Egor Tolstoy. Egor is a full-time iOS developer working at Rambler&Co and living with his lovely wife in Moscow, Russia. In his spare time he investigate iOS applications for different vulnerabilities and blogs about my research.

Parse is a wonderful BaaS which helps with setting up backend infrastructure for your mobile application as fast as possible. Maybe just because of this simplicity many developers forget about a number of new security issues and vulnerabilities.

For those who don’t know what this service is, let’s make a brief introduction. Parse provides a lot of useful capabilities to mobile developer: cloud data storage, push notifications, usage statistics and crash logs gathering, code hosting, background jobs and a many other things. Within the boundaries of thes research we are interested in the cloud data storage, named Cloud Core.
All the data in Cloud Core is stored in so called custom classes (ordinary database tables).

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iOS Application Security Part 37 - Adapting to iOS 8

In this article we will look at all the things you need to do to set up a pentesting platform on iOS 8 and be comfortable with using all the tools.

Jailbreaking your device

If your device is running iOS 8.1 or earlier, you can use pangu to jailbreak your device. The process is prerry straightforward. We will not be covering jailbreaking your device in this article but if you want to know how it is done, you can read this article.

Note: I was getting an error with Pangu saying that there was not enough space on my device even though there was enough space. I tried by putting my device into Airplane mode and by turning off Wifi on my laptop and it worked for me.

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Damn Vulnerable iOS App v1.4 launched

I am so excited to release the latest version of Damn Vulnerable iOS app for iOS 8. Up till now, DVIA has been downloaded more than 75000 times and i can’t wait for the count to reach 6 digits :–)

Following vulnerabilities and challenges have been added in the latest version.

  1. Sensitive information in memory
  2. Webkit Caching (Insecure data storage)
  3. Certificate pinning bypass

You can download the latest version from here. The source code is available on the project’s github page here.

Manual Installation

The easiest way is to install the application from Cydia. Add the source repo.kylelevin.com and search for DamnVulnerableiOSApp.


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Android Application hacking with Insecure Bank Part 1

In this article series, we will learn at various concepts of Android application security while exploiting a vulnerable app InsecureBankv2. We will be looking at all the concepts from a noob’s perspective and hence i would recommend this blog series to beginners as well.

However, the first thing to do is set up a proper mobile pentesting platform for android application testing.

The first thing to do is download the Eclipse ADT bundle. You can then follow the instructions here to install the ADT bundle. Once this is done, make sure you install the necessary sdk packages and libraries by following the instructions here.

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iOS Application Security Part 36 – Bypassing certificate pinning using SSL Kill switch

In this article, we will look at how we can analyze network traffic for applications that use certificate pinning. One of the best definitions i found of certificate pinning is mentioned below. It is taken directly from this url.

By default, when making an SSL connection, the client checks that the server’s certificate:

  • has a verifiable chain of trust back to a trusted (root) certificate
  • matches the requested hostname
  • What it doesn’t do is check if the certificate in question is a specific certificate, namely the one you know your server is using.
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Wifite Walkthrough part 2: Cracking WPA access points

In this article, we will look at cracking access points using WPA-PSK or WPA2-PSK using Wifite.

If you have used tools like airodump-ng, aircrack-ng etc to crack WPA access points before, you would know that the required thing to successfully crack a WPA-PSK network is a captured WPA four-way handshake. More details about the WPA four-way handshake can be found on this wikipedia page.

As mentioned in the previous article, there is a bug in Wifite that may or may not be there in your particular version of Wifite. The bug basically doesn’t aireplay-ng to function properly and displays an error like aireplay-ng exited unexpectedly . In order to fix this, you will have to make slight modifications in the code of wifite. You can install gedit (apt-get install gedit) which is a text editor and then edit the wifite python script (found in /usr/bin/wifite) using the steps mentioned here. To open wifite, use the command gedit /usr/bin/wifite. This will open up the source code of wifite. Then replace every occurence of cmd = [‘aireplay-ng’, with cmd = [‘aireplay-ng’,’–ignore-negative-one’,

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Wifite Walkthrough part 1: Cracking WEP access points

In this article series, we will look at a tool named Wifite suitable for automated auditing of wireless networks. Most of you who have experience in wireless pentesting would use tools like airmon-ng, aireplay-ng, airodump-ng, aircrack-ng to crack wireless networks. This would involve a sequence of steps, like capturing a specific numbers of IV’s in case of WEP, capturing the WPA handshake in case of WPA etc, and then subsequently using aircrack-ng to crack the password required for authentication to the network. Wifite aims to ease this process by using a wrapper over all these tools and thus making it super easy to crack Wifi networks.

Here is a list of features of Wifite as per its official homepage.

  • sorts targets by signal strength (in dB); cracks closest access points first
  • automatically de-authenticates clients of hidden networks to reveal SSIDs
  • numerous filters to specify exactly what to attack (wep/wpa/both, above certain signal strengths, channels, etc)
  • customizable settings (timeouts, packets/sec, etc)
  • “anonymous” feature; changes MAC to a random address before attacking, then changes back when attacks are complete
  • all captured WPA handshakes are backed up to wifite.py’s current directory
  • smart WPA de-authentication; cycles between all clients and broadcast deauths
  • stop any attack with Ctrl+C, with options to continue, move onto next target, skip to cracking, or exit
  • displays session summary at exit; shows any cracked keys
  • all passwords saved to cracked.txt
  • built-in updater: ./wifite.py -upgrade
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iOS Application Security Part 35 – Auditing iOS Applications With iDB

In this article, we will look at another cool utility named iDB for pentesting iOS applications.

Before that, i would like to apologize for coming up late with this article. A lot of you have been requesting articles on different topics and i promise that i will write on them soon :). So since we are best friends again, let’s dive into this tool.

iDB is open source and you can download it from its Github page. You can then follow the tutorial here to know how to install it. Installation might take some time as there might be some dependencies you will have to install, so have some patience. Also, please note that it works with ruby versions 1.9 and 2.1 so make sure you set that version of ruby. You can use rvm list to list the versions of ruby installed on your system and then use rvm use followed by the version of ruby that you want to use.

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iOS Application Security Part 34 - Tracing Method calls using Logify

In the previous articles, we have seen how applications like Snoop-it can trace method calls specific to the application at runtime. This is very important in deducing the flow of the application. The same process can be performed by using a perl script named Logify.pl that comes installed with Theos. The script takes input as a header file and generates the hooking code that we can add in our tweak. We can also specify the classes we want to check. Once the tweak is installed on the device, whenever a method for that particular class is called, the tweak logs out the method along with the arguments to syslog. The first step here is to get the header files for a particular application. You can get the header files by using the -H option in class-dump-z. Once the headers folder is generated, you can copy it to your system.


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