Thread: Google Email Recovery Vulnerability (Removing Secondary E-mail Address -Self Exploit

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#Title: Google Email Recovery Vulnerability (Removing Secondary E-mail Address -Self Exploitation)
#Author: Sandeep Kamble (www.SandeepKamble.com)
#Risk Factor: Low (Why low please read below)
#Attack Type: A User can access B User account Link to remove secondary E-mail address
#Reported Date: OCT 21 , 2011

Overview:

In Google account setting page, when you reset Google account password, it send Reset Password link to your secondary email address. Into that mail there is one more link which can be used remove your secondary email address.

Vulnerability Description:

This Vulnerability can be used to remove secondary email address. In this vulnerability we needed to guess ?C variable token to access the any users account link that can be used to remove secondary email address ?C variable token is generating at sever side so that it is not possible to guess this token and so that it can be performed at victim side only. (Self Exploitation)

Vulnerable Link

https://www.google.com/accounts/Acco...z_7p8Z4B&hl=en
Link it has two options, one option is to remove the Secondary and one option to negated email removing operation.
The above like is accessible to everyone. We cannot generate the token number so we can find the token using

Google Dork: Inurul : /AccountDisavow?c=

If you click on the radio button, “No, I didn't create *******@gmail.com - remove my email address, ********@yahoo.com, from this Google Account. “ and then click continue it will remove the email and delete the link token.
This link will be dead, No one can access it again !

But if you click on the,” Yes, *******@gmail.com is my Google Account. ” and press continue.
When u Click on the this radio button the token is not getting deleted, so that may be pages are indexed into Google

Proof of Concept




Special thanks to Amol Naik , Anil , veenu bhai

Warm Regards

Sandeep Kamble
www.sandeepkamble.com