On 2nd January, Samsung pushed a software update (I9300XXELLA) to the Galaxy S III and we can confirm that the new software update fixes the infamous Exynos 4 vulnerability. The security flaw was in the kernel which made the device R/W by all users, apps and gave access to full Physical Memory. In short, this vulnerability gave root permissions to *any* app and there was no control over it but now with the new system update the security hole has been patched.
We believe that the new system update also fixes the sudden death issue as the new firmware ships with brand new bootloaders and this is the first time Samsung has updated the bootloaders of the device since it started shipping back in May 2012. But, we can't confirm if sudden death issue has been resolved or not as Samsung is the only one who can confirm about the fix.
For now the new software update is only available for the United kingdom (BTU) but we expect other countries to follow soon. We would urge Galaxy S III users to immediatly update their device to the latest firmware via Kies or OTA (Over-The-Air).
Official Firmware Details:
Android Version: 4.1.2 – Build JZO54K
Build Date: 22-12-12
Change list: 742798
UPDATE: Our sources confirm that Samsung has fixed the sudden death issue with the latest Galaxy S III Software Update.