Ruby gem Thumbshooter 0.1.5 remote command execution

3/25/2013
Generates thumbshots of URLs by using Webkit and QT4.

https://github.com/digineo/thumbshooter

Specially crafted URLs can result in remote code execution if the URL contains shell metacharacters.

We see that the url is passed directly to the shell in the following code snippet from ./thumbshooter-0.1.5/lib/thumbshooter.rb lines:

 1012 command << "xvfb-run -a --server-args='-screen 0, #{screen}x24' " 
 1015 command << "{WEBKIT2PNG} '{url}' {args}"
 1017 img = `{command} 2>&1`
Larry W. Cashdollar
@_larry0
http://vapid.dhs.org/advisories/thumbshooter-ruby-gem-remoteexec.html


Larry C$

Larry C$