How to sniff a network traffic on Android ≥ 7

This Note originally published on my Personal Blog here. Read original note so that you won’t miss any content.

Today I want to write about sniffing network traffic on Android. Let me show you what we had before and what we have after Android Nougat:

without network_security_config.xml

In other words, Google removed the feature to sniff a network traffic out of the box in Android Nougat. Furthermore, it means, that you won’t be able to sniff a network traffic in apps from Play Market.

Thereby, we should install network_security_config manually to resurrect sniffing feature. There are two ways to do it:

• add network_security_config.xml in the source
• inject network_security_config.xml in an .apk file

https://developer.android.com/training/articles/security-config

with network_security_config.xml

Addition network_security_config.xml in the source

• default

• custom

But there is a high probability, that Google may reject apps have network_security_config.xml, because it’s “a care” about peace, rock ’n’ roll and safety.

Injection network_security_config.xml in an .apk file

Here we are able to build a release .apk, duplicate it and make a network_security_config.xml injection. So, let’s start:

1. Build an .apk

2. Clone the repo:

$ git clone https://github.com/levyitay/AddSecurityExceptionAndroid.git

3. Run a script from the repo:

$ ./addSecurityExceptions.sh yourApp.apk

• the script unpacks your .apk via apktool
• injects network_security_config.xml into AndroidManifest.xml
• signs and repacks your .apk

4. Your app is ready for test, install it and enjoy the sniffing

Conclusion

Hope it was interesting or at least a little bit useful (:

Thanks for the reading and see you!