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Re: Using Twitter for Phishing Campaign / Spam / Followers?
From: Cal Leeming <cal () foxwhisper co uk>
Date: Tue, 15 Mar 2011 15:10:46 +0000

Agreed. These public API methods should have brute force protection at the
very least. But, because they want instant in-line form validation for email
address availability, this makes it difficult. In an ideal world, they'd
have a CAPTCHA on the form,  and only validate upon submit with valid
captcha.


On Tue, Mar 15, 2011 at 3:02 PM, Reverse Skills
<contact () reverseskills com>wrote:

The problem is to allow unlimited access to that resource, not the
resource itself.

2011/3/15 Cal Leeming <cal () foxwhisper co uk>:
This conceptual flaw exists in most web apps which have a "reset password
by
email address" feature, as most will display an error if the email
address
does not exist in their database.

On Tue, Mar 15, 2011 at 12:19 PM, Reverse Skills <
contact () reverseskills com>
wrote:

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 Rockyou / Singles.org / Gawker /
Rootkit.com or just a typical dictionaries and domains will be quite
easy to get hold of a list of users large enough (* () 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
--

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

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

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