Undocument bug on Cisco CSS series 11000 with Webns 8.20.0.1

Cisco CSS series 11000 with webns system and ssh daemon crash on  ssh 
crc32 old 2001 exploit

Cisco CSS :
Webns Version:  08.20.0.01  (using command sh ver)
SSH Version: SSHield version 1.6.1, SSH version OpenSSH_3.0.2p1 (using 
command sh sshd version)

CSS is default configured with max 5 concurrency session

with old shack exploit css does not relase connection and when it get 5 
connection it crashes with no other possibility of connection

Alessandro Fiorenzi  aka NetExpress