The ugidd RPC interface, by design, allows remote attackers to enumerate valid usernames by specifying arbitrary UIDs that ugidd maps to local user and group names.
Linux 2.1.132 and earlier allows local users to cause a denial of service (resource exhaustion) by reading a large buffer from a random device (e.g. /dev/urandom), which cannot be interrupted until the read has completed.
Bug in AMD K6 processor on Linux 2.0.x and 2.1.x kernels allows local users to cause a denial of service (crash) via a particular sequence of instructions, possibly related to accessing addresses outside of segments.