LEAKED FIRMWARE INFO
Firmware Version N900AUCUCNC2
Android Version Android 4.4.2 KitKat
Is this Official? YES! This is an OTA update.
Stability Full stability.
Credits baddison (for providing the OTA update file)

  Known Bugs/Issues

  • None so far

  WARNING!

This update contains a new bootloader due to which downgrading to previous stock firmwares WILL NOT BE POSSIBLE.

As of yet, root CAN NOT be retained or acquired on this build (N900AUCUCNC2).

Warranty may be void of your device if you follow the procedures given on this page.

You only are responsible for your device. We won’t be liable if any damage occurs to your device and/or its components.

  AT&T GALAXY NOTE 3 SM-N900A ANDROID 4.4.2 KITKAT OTA UPDATE

Before you begin with the instructions below, make sure your android device is adequately charged — at least 50% battery of the device.

  STEP 0: CHECK DEVICE MODEL NO.

To make sure your device is eligible with this, you must first confirm its model no. in ‘About device’ option under Settings. Another way to confirm model no. is by looking for it on the packaging box of your device. It must be SM-N900A!

Do not use the procedures discussed here on any other Galaxy NOTE 3 (including the Galaxy NOTE 3 variant at Sprint, Verizon, US Cellular, T-Mobile and other International variants) or any other device of Samsung or any other company. You have been warned!

  STEP 1: BACKUP YOUR DEVICE

Back up important data and stuff before you start playing around here as there are chances you might lose your apps and app-data (app settings, game progress, etc.), and in rare case, files on the internal memory, too.

For help on Backup and Restore, check out our exclusive page on that linked right below.

► ANDROID BACK UP AND RESTORE GUIDE: APPS AND TIPS

  STEP 2: YOU MUST HAVE STOCK N900AUCUBNB4 (aka NB4) FIRMWARE INSTALLED

NOTE: Skip this step if you’re already on stock N900AUCUBNB4 firmware with no root and no custom recovery installed.

However, if you’ve installed the previously leaked Android 4.4.2 update on your AT&T Galaxy NOTE 3 then you’ll need to revert back to N900AUCUBMJ5 (aka MJ5) firmware first and then take the OTA update to NB4 firmware.

It’s required that you are unrooted, and don’t have a custom recovery (CWM or TWRP) installed. Plus, no custom firmwares, either.

So follow the link below for instructions on how to revert back to the MJ5 firmware. The link below also has instructions to root the MJ5 firmware, but you make sure that you don’t root your device.

Just install the MJ5 firmware, then take the NB4 firmware OTA update and then follow the rest of the guide below to install the N900AUCUCNC2 OTA update on your AT&T Galaxy NOTE 3.

 icon-hand-o-right INSTALL ANDROID 4.3 MJ5 FIRMWARE (Don’t root it!)

   STEP 3: INSTALLATION INSTRUCTIONS

  DOWNLOADS

Download the firmware file given below.

  OTA FILE

DOWNLOAD LINK  | File name: 2400258.cfg (554 MB)

  STEP-BY-STEP GUIDE

Important Note: Backup important files stored on internal SD card of your device, so that in case a situation arises requiring you to do a factory reset after flashing the leaked firmware, which might delete internal sd card too, your files will remain safe on PC.

  1. Make sure you are running NB4 firmware for your AT&T Galaxy NOTE 3. And that it’s not rooted, and has stock recovery installed, NOT CWM/TWRP recovery. If not, follow the link in Step 2 above to install the MJ5 firmware first (without root) and then take NB4 OTA update.
    └ If you skip this step then you won’t be able to update to Android 4.4.2 using this guide.
  2. Rename the OTA file that you downloaded from the link above to change its extension to .zip. The new file name should then be 2400258.zip
  3. Transfer the 2400258.zip file to root of your phone’s internal or external SD card
    └ Note that you must put the 2400258.zip file in the root directory of either storage. Don’t put the file inside any folder on your card.
  4. Boot into Recovery mode:
    • Power off your phone and wait for few seconds until it’s completely powered off.
    • Hold down the following three buttons together ‘Home + Power + Volume UP‘ and release them as soon as you see the Samsung Galaxy NOTE 3 logo on the device’s screen. This will boot your phone into recovery mode. It must be saying 3e recovery at the top. If not, it’s not stock recovery and you haven’t read the above carefully. Pls do now.
      └ Once in recovery, use Volume buttons to navigate between options and Power button to select an option. And if you need further help with booting into recovery mode, check our Galaxy NOTE 3 Recovery Mode help page.
  5. Now select ‘Apply update.zip‘ if you transferred the file to internal SD card OR select ‘Apply update from external storage‘ if you transferred the file to external storage.
  6. Wait for the device to finish the flashing process. Once it’s done, select Reboot from the main menu in recovery.

That’s it. You’re done.

Let us know in the comments below if you need further help with the guide above. We’d be happy to help.