Operating systems with shared memory implementations based on BSD 4.4 code allow a user to conduct a denial of service and bypass memory limits (e.g., as specified with rlimits) using mmap or shmget to allocate memory and cause page faults.
Sysinstall in FreeBSD 2.2.1 and earlier, when configuring anonymous FTP, creates the ftp user without a password and with /bin/date as the shell, which could allow attackers to gain access to certain system resources.
A design flaw in the Z-Modem protocol allows the remote sender of a file to execute arbitrary programs on the client, as implemented in rz in the rzsz module of FreeBSD before 2.1.5, and possibly other programs.