in the behalf of any logged in user.
Hmm, it seems interesting but still not exploitable, as there is no way for an attacker to get the “Auth” value from a victim session.
2- Bypassing the CSRF Auth System:
The CSRF Auth verifies every single request of that user, So what If an attacker “not logged in” tries to make a “send money” request then PayPal will ask the attacker to provide his email and password, The attacker will provide the “Victim Email” and ANY password, Then he will capture the request, The request will contain a Valid CSRF Auth token Which is Reusable and Can authorise this specific user requests. Upon Further Investigation, We have found out that an Attacker can obtain the CSRF Auth which can be valid for ALL users, by intercepting the POST request from a page that provide an Auth Token before the Logging-in process, check this page for the magical CSRF Auth “https://www.paypal.com/eg/cgi-bin/webscr?cmd=_send-money”. At this point the attacker Can CSRF “almost” any request on behalf of this user.
The application generates a valid "Auth" token for a logged-out user!
http://www.movilta.tk/
http://sh.st/fdcAe
http://sh.st/fdcKM
http://sh.st/d7CpS
http://sh.st/d7XAO
http://sh.st/fdc8E
http://sh.st/fdnIw
http://d2022.jimdo.com/
FacebookThe application generates a valid “Auth” token for a logged-out user!
Through examination of the password change process, I have found that an attacker can NOT Change the victim password without answering the Security Questions set by user, Also the user himself can NOT change the security questions without entering the password!
3- ByPassing the Security Questions Change:
Screen Shot 2015
The initial process of “setting” security questions is not password protected and is reusable
After further investigation, I have noticed that the request of setting up the security questions “which is initiated by the user while signing up” is not password-protected, and it can be reused to reset the security questions up without providing the password, hence, Armed with the CSRF Auth, an attacker can CSRF this process too and change the victim’s Security questions.
At this point, An attacker can
conduct a targeted CSRF attack against a PayPal users and take a full
control over his account Hence, An attacker can CSRF all the requests
including but not limited to:1- Add/Remove/Confirm Email address
2-Add fully privileged users to business account
3- Change Security questions
4- Change Billing/Shipping Address
5- Change Payment methods
6- Change user settings(Notifications/Mobile settings) ………… and more.
To automate the who process, I have coded a Python interactive server to demonstrate how an attacker can exploit this vulnerability in a real-life scenario attack.
2015
08.04
Microsoft-careers.com Remote Password Reset
Category: Security / Tag: Bug Bounty, Microsoft Security / 2 comments
Today I am going to share this interesting vulnerability which allowed me to change the passwords of all Microsoft Careers users. Microsoft-careers.com is the Microsoft official recruiting website where millions of people around the world has their CV’s uploaded there. As a Job seeker :), I have registered and uploaded my resume there, a month later, I tried to log in my account but as usual, I forgot my password :( I went to “Forget my password” page and entered my Email, I checked my email and found a message including this reset password link ( https://www.microsoft-careers.com/reset/ED504CCE-5056-9214-016F355013806D75/) After clicking the link, I have been presented to a page where I should enter my new password, hmmmmm.. I fired up Burpsuite and intercepted the request was looks like
Microsoft-careers hacked
As we can see in this POST request, the (id) value is being sent with the request, with No authorisation key, So I have changed the ID value to the ID of my test account, And YES, I cold change my test account password :). Imagine if we made a small Python code to automate this process, We can change all the password of all users within hours. After reporting this vulnerability to Microsoft, They have patched it and added my name to their Wall of Fame
