This indicates an attack attempt against a buffer overflow vulnerability in IBM Informix Products Setnet32 Utility.
The vulnerability is caused by an error when the vulnerable software handles a malicious .nfx file. It allows a remote attacker to execute arbitrary code via sending a crafted .nfx file.
IBM Informix Client Software Development Kit (CSDK) 3.5
IBM Informix Connect 3.x
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are not aware of any vendor supplied patch for this issue.