# Exploiting a debuggeable application
Learn AWS hacking from zero to hero with htARTE (HackTricks AWS Red Team Expert)!
Other ways to support HackTricks:
* If you want to see your **company advertised in HackTricks** or **download HackTricks in PDF** Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
* **Join the** š¬ [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** š¦ [**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
# **Bypassing root and debuggeable checks**
This section of the post is a summary from the post [**https://medium.com/@shubhamsonani/hacking-with-precision-bypass-techniques-via-debugger-in-android-apps-27fd562b2cc0**](https://medium.com/@shubhamsonani/hacking-with-precision-bypass-techniques-via-debugger-in-android-apps-27fd562b2cc0)
## Steps to Make an Android App Debuggable and Bypass Checks
### **Making the App Debuggable**
Content based on https://medium.com/@shubhamsonani/hacking-with-precision-bypass-techniques-via-debugger-in-android-apps-27fd562b2cc0
1. **Decompile the APK:**
- Utilize the APK-GUI tool for decompiling the APK.
- In the _android-manifest_ file, insert `android:debuggable=true` to enable debugging mode.
- Recompile, sign, and zipalign the modified application.
2. **Install the Modified Application:**
- Use the command: `adb install `.
3. **Retrieve the Package Name:**
- Execute `adb shell pm list packages ā3` to list third-party applications and find the package name.
4. **Set the App to Await Debugger Connection:**
- Command: `adb shell am setup-debug-app āw `.
- **Note:** This command must be run each time before starting the application to ensure it waits for the debugger.
- For persistence, use `adb shell am setup-debug-app āw -āpersistent `.
- To remove all flags, use `adb shell am clear-debug-app `.
5. **Prepare for Debugging in Android Studio:**
- Navigate in Android Studio to _File -> Open Profile or APK_.
- Open the recompiled APK.
6. **Set Breakpoints in Key Java Files:**
- Place breakpoints in `MainActivity.java` (specifically in the `onCreate` method), `b.java`, and `ContextWrapper.java`.
### **Bypassing Checks**
The application, at certain points, will verify if it is debuggable and will also check for binaries indicating a rooted device. The debugger can be used to modify app info, unset the debuggable bit, and alter the names of searched binaries to bypass these checks.
For the debuggable check:
1. **Modify Flag Settings:**
- In the debugger console's variable section, navigate to: `this mLoadedAPK -> mApplicationInfo -> flags = 814267974`.
- **Note:** The binary representation of `flags = 814267974` is `11000011100111011110`, indicating that the "Flag_debuggable" is active.
These steps collectively ensure that the application can be debugged and that certain security checks can be bypassed using the debugger, facilitating a more in-depth analysis or modification of the application's behavior.
Step 2 involves changing a flag value to 814267972, which is represented in binary as 110000101101000000100010100.
# **Exploiting a Vulnerability**
A demonstration was provided using a vulnerable application containing a button and a textview. Initially, the application displays "Crack Me". The aim is to alter the message from "Try Again" to "Hacked" at runtime, without modifying the source code.
## **Checking for Vulnerability**
- The application was decompiled using `apktool` to access the `AndroidManifest.xml` file.
- The presence of `android_debuggable="true"` in the AndroidManifest.xml indicates the application is debuggable and susceptible to exploitation.
- It's worth noting that `apktool` is employed solely to check the debuggable status without altering any code.
## **Preparing the Setup**
- The process involved initiating an emulator, installing the vulnerable application, and using `adb jdwp` to identify Dalvik VM ports that are listening.
- The JDWP (Java Debug Wire Protocol) allows debugging of an application running in a VM by exposing a unique port.
- Port forwarding was necessary for remote debugging, followed by attaching JDB to the target application.
## **Injecting Code at Runtime**
- The exploitation was carried out by setting breakpoints and controlling the application flow.
- Commands like `classes` and `methods ` were used to uncover the applicationās structure.
- A breakpoint was set at the `onClick` method, and its execution was controlled.
- The `locals`, `next`, and `set` commands were utilized to inspect and modify local variables, particularly changing the "Try Again" message to "Hacked".
- The modified code was executed using the `run` command, successfully altering the applicationās output in real-time.
This example demonstrated how the behavior of a debuggable application can be manipulated, highlighting the potential for more complex exploits like gaining shell access on the device in the application's context.
## References
* [https://medium.com/@shubhamsonani/hacking-with-precision-bypass-techniques-via-debugger-in-android-apps-27fd562b2cc0](https://medium.com/@shubhamsonani/hacking-with-precision-bypass-techniques-via-debugger-in-android-apps-27fd562b2cc0)
* [https://resources.infosecinstitute.com/android-hacking-security-part-6-exploiting-debuggable-android-applications](https://resources.infosecinstitute.com/android-hacking-security-part-6-exploiting-debuggable-android-applications)
Learn AWS hacking from zero to hero with htARTE (HackTricks AWS Red Team Expert)!
Other ways to support HackTricks:
* If you want to see your **company advertised in HackTricks** or **download HackTricks in PDF** Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
* **Join the** š¬ [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** š¦ [**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.