The malloc subsystem in libc in IBM AIX 5.3 and 6.1 allows local users to create or overwrite arbitrary files via a symlink attack on the log file associated with the MALLOCDEBUG environment variable.
https://www.exploit-db.com/exploits/9306
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6276
https://exchange.xforce.ibmcloud.com/vulnerabilities/50636
http://www.vupen.com/english/advisories/2009/1380
http://www.securityfocus.com/bid/35034
http://www.ibm.com/support/docview.wss?uid=isg1IZ50517
http://www.ibm.com/support/docview.wss?uid=isg1IZ50500
http://www.ibm.com/support/docview.wss?uid=isg1IZ50447
http://www.ibm.com/support/docview.wss?uid=isg1IZ50445
http://www.ibm.com/support/docview.wss?uid=isg1IZ50139
http://www.ibm.com/support/docview.wss?uid=isg1IZ50129
http://www.ibm.com/support/docview.wss?uid=isg1IZ50121
http://securitytracker.com/id?1022261
http://secunia.com/advisories/35146
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=802
http://aix.software.ibm.com/aix/efixes/security/libc_advisory.asc