This indicates an attack attempt against a buffer overflow vulnerability in AIX Calendar Manager Service Daemon.
The vulnerability is caused by an error when the vulnerable software handles a malicious rpc request. It allows a remote attacker to execute arbitrary code via sending a crafted request.
IBM AIX 5.x through 5.3.10 and 6.x through 6.1.3, and VIOS 2.1 and earlier
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patch, please Refer to the vendor's web site for suggested workaround.