Some Kit Kat devices with the MediaTek Chipset that run Kit Kat Android 4.4 have a vulnerability. This vulnerability allows for exploits that could gain root access on your phone. Once a hacker has access they could even brick your phone or spy on calls and texts. Security Expert "Jcase" tweeted about the bug earlier in the month, and MediaTek is finally confirming that the bug does exists. According to MeidaTek they instructed OEMs to disable debug before shipping phones. MediaTek has decided to not release a list of vulnerable devices. Just to be safe you will want to upgrade your device from Kit Kat as soon as an update is available. MediaTek says they will inform manufacturers whose phones have the vuln.
via Gadgets360