RC.BOOT in IBM AIX 5.1, 5.2, and 5.3 does not "use a secure location for temporary files," which allows local users to have an unknown impact, probably by overwriting files.
ftpd in IBM AIX 5.1, 5.2 and 5.3 allows remote authenticated users to cause a denial of service (port exhaustion and memory consumption) by using all ephemeral ports.
rmmlcachefile in bos.rte.install in AIX 5.1.0 through 5.3.0 allows local users to overwrite arbitrary files via a symlink attack on temporary files.