It's things like CGI scripts that are vulnerable, deep within a website (like CPanel's /cgi-sys/defaultwebpage.cgi)," Graham wrote in a blog post. "Getting just the root page is the thing least likely to be vulnerable. Spidering the site and testing well-known CGI scripts (like the CPanel one) would give a lot more results—at least 10x."
In addition, Graham said, "this thing is clearly wormable and can easily worm past firewalls and infect lots of systems. One key question is whether Mac OS X and iPhone DHCP service is vulnerable—once the worm gets behind a firewall and runs a hostile DHCP server, that would be 'game over' for large networks."
"Researchers on Thursday discovered a critical remotely exploitable vulnerability in the widely used command-line shell GNU Bourne Again Shell (Bash), dubbed "Shellshock" which affects most of the Linux distributions and servers worldwide, and may already have been exploited in the wild to take over Web servers as part of a botnet that is currently trying to infect other servers as well."