The setsockopt call in the KAME Project IPv6 implementation, as used in FreeBSD 5.2, does not properly handle certain IPv6 socket options, which could allow attackers to read kernel memory and cause a system panic.
The jail_attach system call in FreeBSD 5.1 and 5.2 changes the directory of a calling process even if the process doesn't have permission to change directory, which allows local users to gain read/write privileges to files and directories within another jail.
FreeBSD 5.1 and earlier, and Mac OS X before 10.3.4, allows remote attackers to cause a denial of service (resource exhaustion of memory buffers and system crash) via a large number of out-of-sequence TCP packets, which prevents the operating system from creating new connections.
The TCP MSS (maximum segment size) functionality in netinet allows remote attackers to cause a denial of service (resource exhaustion) via (1) a low MTU, which causes a large number of small packets to be produced, or (2) via a large number of packets with a small TCP payload, which cause a large number of calls to the resource-intensive sowakeup function.
The shmat system call in the System V Shared Memory interface for FreeBSD 5.2 and earlier, NetBSD 1.3 and earlier, and OpenBSD 2.6 and earlier, does not properly decrement a shared memory segment's reference count when the vm_map_find function fails, which could allow local users to gain read or write access to a portion of kernel memory and gain privileges.