VDB-ID: 56
Title: Vulnerability Report for Ruby Gem gyazo-1.0.0
Vulnerability Date: 2014-06-01
Download: http://rubygems.org/gems/gyazo
Vendor: Toshiyuki Masui
Notified: 2014-06-25
Vendor Contact: masui[at]pitecan.com
Description: Upload an image to Gyazo.com.
Vulnerability: From: ./gyazo-1.0.0/lib/gyazo/client.rb

If this Gem is used in the context of a rails app a malicious user may inject commands via #{imagefile} and #{tmpfile} using shell meta characters like ; and sending an escaped \".

0through the {imagefile} name if the raw option is not set. Also file names are time based and predictable leading to file clobbering vulnerabilities as the running process username.

 57       unless opts[:raw]
 58         tmpfile = "/tmp/gyazo_upload_{Time.now.to_i}_{Time.now.usec}.png"
 59         if File.exist? imagefile
 60           system "sips -s format png \"{imagefile}\" --out \"#{tmpfile}\" > /dev/null"
 61         end
 62       end

CVE-IDs: 2014-4994
Exploit: 
URL: http://www.vapid.dhs.org/advisories/gyazo-1.0.0.html
Credit: Larry W. Cashdollar, @_larry0