The AT&T Galaxy S4 Bootloader has been hacked, yes boys & girls, nerds & fanboys, you read it right, the bootloader on the AT&T Samsung bootloader has been hacked!.
Dan Rosenberg aka @djrbliss just tweeted the above picture, it says “Samsung Galaxy S4 bootloader hacked by Dan Rosenberg (djrbliss).”. Even though we have no confirmation from Dan that’s it for AT&T Samsung Galaxy S4 but considering the bootloader on the AT&T Samsung Galaxy S4 is the only one which is locked, it’s obvious that he has hacked the bootloader on the AT&T Samsung Galaxy S4.
We will keep you updated once the how to do it is available.
djrbliss has confirmed that the picture above infact is the AT&T Samsung Galaxy S4, and it does allow to flash custom kernels and recoveries, the release will not be until the Verizon Galaxy S4 starts shipping (which will be in late May). The reason for the delayed release being that Verizon is notorious for locking bootloaders as well and in all probability the bootloader on the Verizon Samsung Galaxy S4 will be locked as well, to prevent his exploit from being patched (in case it is released) the release of the exploit has been delayed which makes sense.
Also, we and djrbliss ask you not to take any updates if you want to unlock your bootloader once the exploit is made public.
Source:- djrbliss & xda