The AT&T subscribers of Samsung Galaxy S4 Active (SGH-I537) who wish  to root their devices running on Android 4.2.2 Jelly Bean, may follow  the tutorial below.

This tutorial uses activeroot file released by famed iPhone and PS3  hacker, geohot. This is a quick and simple method. The activeroot file  allowing users to root Galaxy S4 Active directly from their devices.
Disclaimer: 
Rooting voids the warranty of your device. We and the  developer of this rooting procedures shall not be held responsible if  any undesirable outcomes may happen to your device. use of this root  guide is solely at your own risk!Pre-requisites1. Enable "Unknown sources" on the phone to allow installation of apps  from sources other than the Play Store by navigating to Settings  >> Security.
2. The activeroot file works only on Samsung Galaxy S4 Active (AT&T)  SGH-I537. Verify the model number of the Galaxy S4 Active by navigating  to Settings >> About Phone.
Steps to Root Galaxy S4 Active (AT&T) SGH-I537 Running on Android 4.2.2 Jelly Bean FirmwareStep 1: Download the 
activeroot file (
ar.apk) directly from your device.
Step 2: Run the 
ar.apk file on your device. It should give you a message telling you that you have root.
Step 3: Visit the Google Play Store and install 
SuperSU.
Note: 
You MUST download and use SuperSU to manage  superuser permissions, nothing else. Only SuperSU currently can  circumvent Samsung’s “root blocker” in the kernel.Step 4: Once the installation process is completed, open the SuperSU app and update binaries.
Step 5 (optional): Donate. Credit goes to geohot for his great work.
Samsung Galaxy S4 Active (AT&T) SGH-I537 running on Android 4.2.2  Jelly Bean firmware is now rooted successfully. You can now install any  app that requires root permission. Verify the root status of the device  by downloading 
Root Checker app from Google Play Store.
Note: Many Samsung devices store a flash counter that keeps track of how many times you have flashed custom firmwares to your device. Triangle Away can be used to reset the flash counter to zero.Thank's to all fellas at XDA who first tried out this rooting technique. This method was originally posted via XDA-Developers 
original thread.