This script is Copyright (C) 2001-2014 Tenable Network Security, Inc.
It is possible to execute arbitrary code on the remote host.
The remote /bin/login seems to crash when it receives too many
environment variables. This is likely due to a buffer overflow
vulnerability which might allow an attacker to execute arbitrary code
on the remote host.
Apply the patch from your vendor (or read the CERT advisory).
Risk factor :
Critical / CVSS Base Score : 10.0
CVSS Temporal Score : 8.3
Public Exploit Available : true