Buffer overflow in enq command in IBM AIX 4.3.x and earlier may allow local users to execute arbitrary commands via a long -M argument.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5619
http://www.securityfocus.com/bid/2034
http://www-1.ibm.com/support/search.wss?rs=0&q=IY08287&apar=only
http://www-1.ibm.com/support/search.wss?rs=0&q=IY08143&apar=only