Buffer overflow in paginit in AIX 5.1 through 5.3 allows local users to execute arbitrary code via a long username.
https://exchange.xforce.ibmcloud.com/vulnerabilities/18618
http://www-1.ibm.com/support/search.wss?rs=0&q=IY64522&apar=only
http://www-1.ibm.com/support/search.wss?rs=0&q=IY64358&apar=only
http://www-1.ibm.com/support/search.wss?rs=0&q=IY64312&apar=only