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.
Buffer overflow in the Linux binary compatibility module in FreeBSD 3.x through 5.x allows local users to gain root privileges via long filenames in the linux shadow file system.
BitchX IRC client does not properly cleanse an untrusted format string, which allows remote attackers to cause a denial of service via an invite to a channel whose name includes special formatting characters.
Buffer overflow in Canna input system allows remote attackers to execute arbitrary commands via an SR_INIT command with a long user name or group name.
FreeBSD, NetBSD, and OpenBSD allow an attacker to cause a denial of service by creating a large number of socket pairs using the socketpair function, setting a large buffer size via setsockopt, then writing large buffers.