twitter.com

Simple and easy way to get a list of email accounts used on Twitter. For Phishing campaigns, custom Spam...

Twitter has been notified and I suppose someday be fixed if they think there should be filtered.

When you create a new Twitter account, the form requesting a mailing address. Twitter verify that the email account is not being used, but does not check any user token or limit the usage (captcha/block).

https://twitter.com/signup -> http://twitter.com/users/email_available?email=

We just need to automate it with a simple script , ***Everything you do will be your responsibility***
-------------------
#!/usr/bin/python
import sys, json, urllib2, os

f = urllib2.urlopen("http://twitter.com/users/email_available?email="+sys.argv[1])
data = json.load(f)
def valid()
..
Email has already been taken" in data ["msg"] <-- reply
..
-------------------

We just need a list of users to test.. for example : http://twitter.com/about/employees  (don't be evil is just an example!)
Parsing the name/nickname and testing the {user}@twitter.com a few minutes later we have a list of ~ 400 valid internal email  *@twitter.com. An attacker could probably.. a brute force attack (Google Apps), would send Phishing or try to exploit some browser bugs or similar. #Aurora #Google. Most of these e-mail are internal, not public..
There are also some that make you think they are used to such A-Directory system users :
..
apache@twitter.com
root@twitter.com
mail@twitter.com
..

But, if you download a database Gawker / Rootkit.com or just a typical dictionaries and domains will be quite easy to get a huge list of valid users (*@hotmail.com, *@gmail.com, etc).For example in my case I used to find user accounts in a pentest of a company that used Twitter. But probably not a good idea to allow unlimited access, a malicious user could use these user lists for Spam or Phishing.

--
Security Researcher
http://twitter.com/revskills
--