This indicates an attack attempt against a Buffer Overflow vulnerability in Citrix Provisioning Services.
The vulnerability is caused by an error when the software handles a specially crafted packet. It allows a remote attacker to execute arbitrary code.
The vulnerability is reported in versions 5.6 and prior.
System Compromise: Remote attackers can gain control of vulnerable systems.
Update to version 5.6 SP1 or apply a hotfix
English - http://support.citrix.com/article/CTX127123
Customers using Provisioning Services earlier than version 5.6, should apply the hotfix . These hotfixes can be found at the following locations:
Citrix Provisioning Services 5.1 SP2:
English - http://support.citrix.com/article/CTX127164
Japanese - http://support.citrix.com/article/CTX127166
Citrix Provisioning Services 5.1 SP1:
English - http://support.citrix.com/article/CTX127155
Citrix Provisioning Services 5.1:
English - http://support.citrix.com/article/CTX127175