dhcpcd before 6.10.0, as used in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-04-01 and other products, mismanages option lengths, which allows remote attackers to execute arbitrary code or cause a denial of service (heap-based buffer overflow) via a malformed DHCP response, aka internal bug 26461634.