The bug affects devices with Exynos 4210 and 4412 processors and was first made public by an XDA Developers forum member. If exploited, the vulnerability could allow for malicious application installation and enable an attacker to obtain root privileges on affected devices. Samsung says it plans to provide a software update to address the bug as quickly as possible. The issue may arise only when a malicious application is operated on the affected devices; however, this does not affect most devices operating credible and authenticated applications.
Source: https://threatpost.com/samsung-acknowledges-exynos-root-exploit-122012/77338/