Integer overflow in the fcount counter in FreeBSD before 4.2 through 5.0 allows local users to cause a denial of service (crash) and possibly execute arbitrary code via multiple calls to (1) fpathconf and (2) lseek, which do not properly decrement fcount through a call to fdrop.

Race condition in exec in OpenBSD 4.0 and earlier, NetBSD 1.5.2 and earlier, and FreeBSD 4.4 and earlier allows local users to gain privileges by attaching a debugger to a process before the kernel has determined that the process is setuid or setgid.

The undocumented semconfig system call in BSD freezes the state of semaphores, which allows local users to cause a denial of service of the semaphore system by using the semconfig call.

The access permissions for a UNIX domain socket are ignored in Solaris 2.x and SunOS 4.x, and other BSD-based operating systems before 4.4, which could allow local users to connect to the socket and possibly disrupt or control the operations of the program using that socket.