The kernel in Apple iOS before 5 and Apple TV before 4.4 does not properly recover memory allocated for incomplete TCP connections, which allows remote attackers to cause a denial of service (resource consumption) by making many connection attempts.
The stateless address autoconfiguration (aka SLAAC) functionality in the IPv6 networking implementation in Apple iOS before 4.3 and Apple TV before 4.2 places the MAC address into the IPv6 address, which makes it easier for remote IPv6 servers to track users by logging source IPv6 addresses.