Is QNX4's TCP/IP known as vulnerable? Or not?

I need my QNX v4.25G+Security patch box to be on the Internet.

Currently I use TCP/IP v5.0 (still a beta).

I plan to use a hardware firewall for the basic filterings, no unneeded services are running on QNX, just SSH2 server.

Are there any exploits and attack-tools against TCP/IP v2.45D and|or TCP/IP v5.0?

All those “teardrops”, “boink”, “ping of death” badware that were used against earlier widoze realisations of TCP/IP stack… Or buffer overflows in Tcpip and Socklet themselves?

Please share your experience of using QNX4 in real life environment.