CCITCPGW is one of CA'S TCPIP APPLICATIONS.
An outside program is trying to connect to this mainframe (from another mainframe, windows or unix), which is the default port for CCITCPGW.
Addr = 188.8.131.52
Somewhere in this outside program, it also has the port number that CCITCPGW is using 7000.
CCITCPGW is attempting to use this unrecognized data, transmitted by this outside program.
This results in CAS9899E TASK 0029 ERROR: INVALID PACKET HEADER RECEIVED.
INVALID CTH will always be some non cci user trying to send data to CCI (in error).
Then stops, because the user program cancels...
There is no way for CA/CCI support to block anyone who tries this.