ppp utility in FreeBSD 4.1.1 and earlier does not properly restrict access as specified by the "nat deny_incoming" command, which allows remote attackers to connect to the target system.
telnetd in FreeBSD 4.2 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service by specifying an arbitrary large file in the TERMCAP environmental variable, which consumes resources as the server processes the file.
Buffer overflow in catopen() function in FreeBSD 5.0 and earlier, and possibly other OSes, allows local users to gain root privileges via a long environmental variable.
The catopen function in FreeBSD 5.0 and earlier, and possibly other OSes, allows local users to read arbitrary files via the LANG environmental variable.
The setlocale function in FreeBSD 5.0 and earlier, and possibly other OSes, allows local users to read arbitrary files via the LANG environmental variable.