Title:
======
Paypal Bug Bounty #20 - Persistent Web Vulnerabilities
Date:
=====
2013-01-25
References:
===========
http://www.vulnerability-lab.com/get_content.php?id=682
PayPal UID: fxv444khi
VL-ID:
=====
682
Common Vulnerability Scoring System:
====================================
3.5
Introduction:
=============
PayPal is a global e-commerce business allowing payments and money transfers to be made through the Internet. Online money
transfers serve as electronic alternatives to paying with traditional paper methods, such as checks and money orders. Originally,
a PayPal account could be funded with an electronic debit from a bank account or by a credit card at the payer s choice. But some
time in 2010 or early 2011, PayPal began to require a verified bank account after the account holder exceeded a predetermined
spending limit. After that point, PayPal will attempt to take funds for a purchase from funding sources according to a specified
funding hierarchy. If you set one of the funding sources as Primary, it will default to that, within that level of the hierarchy
(for example, if your credit card ending in 4567 is set as the Primary over 1234, it will still attempt to pay money out of your
PayPal balance, before it attempts to charge your credit card). The funding hierarchy is a balance in the PayPal account; a
PayPal credit account, PayPal Extras, PayPal SmartConnect, PayPal Extras Master Card or Bill Me Later (if selected as primary
funding source) (It can bypass the Balance); a verified bank account; other funding sources, such as non-PayPal credit cards.
The recipient of a PayPal transfer can either request a check from PayPal, establish their own PayPal deposit account or request
a transfer to their bank account.
PayPal is an acquirer, performing payment processing for online vendors, auction sites, and other commercial users, for which it
charges a fee. It may also charge a fee for receiving money, proportional to the amount received. The fees depend on the currency
used, the payment option used, the country of the sender, the country of the recipient, the amount sent and the recipient s account
type. In addition, eBay purchases made by credit card through PayPal may incur extra fees if the buyer and seller use different currencies.
On October 3, 2002, PayPal became a wholly owned subsidiary of eBay. Its corporate headquarters are in San Jose, California, United
States at eBay s North First Street satellite office campus. The company also has significant operations in Omaha, Nebraska, Scottsdale,
Arizona, and Austin, Texas, in the United States, Chennai, Dublin, Kleinmachnow (near Berlin) and Tel Aviv. As of July 2007, across
Europe, PayPal also operates as a Luxembourg-based bank.
On March 17, 2010, PayPal entered into an agreement with China UnionPay (CUP), China s bankcard association, to allow Chinese consumers
to use PayPal to shop online.PayPal is planning to expand its workforce in Asia to 2,000 by the end of the year 2010.
Between December 4ñ9, 2010, PayPal services were attacked in a series of denial-of-service attacks organized by Anonymous in retaliation
for PayPal s decision to freeze the account of WikiLeaks citing terms of use violations over the publication of leaked US diplomatic cables.
(Copy of the Homepage: www.paypal.com) [http://en.wikipedia.org/wiki/PayPal]
Abstract:
=========
The Vulnerability Laboratory Research Team discovered a Web Vulnerability in Paypal Labs Fundraising Widget Web Application.
Report-Timeline:
================
2012-08-13: Researcher Notification & Coordination
2012-08-14: Vendor Notification
2012-09-13: Vendor Response/Feedback
2013-01-12: Vendor Fix/Patch (PayPal Inc)
2013-01-25: Public Disclosure
Status:
========
Published
Exploitation-Technique:
=======================
Remote
Severity:
=========
Medium
Details:
========
Multiple persistent input validation vulnerabilities are detected in Paypal Labs Fundraising Widget. The bugs allow remote attackers
to implement/inject malicious script code on the application side (persistent).
The persistent vulnerabilities are located in the Generate Widgets module with the bound vulnerable your name, your website,
image url and supporters parameter listing. Attackers can inject own malicious script code as name, website url, image url or as
supporter link to generate evil fundraising widgets. The execution of the script code occurs in the main listing out of the account
index or the generated widget file output listing.
Exploitation requires low user interaction or low privileged application user account. Successful exploitation of the vulnerability leads
to persistent session hijacking (admin/mod/customer), account steal via persistent web attack or stable (persistent) context manipulation.
Vulnerable Service(s):
[+] Fundraising Widgets [https://giving.paypallabs.com/]
Vulnerable Module(s):
[+] Generate Widgets
Vulnerable Parameter(s):
[+] your name
[+] your website
[+] image url
[+] supporters
Affected Section(s):
[+] Giving PaypalLabs Account Index
[+] Generated widget output file
Proof of Concept:
=================
The persistent web vulnerabilities can be exploited by remote attackers with low privileged application user account and with low or medium
required user inter action. For demonstration or reproduce ...
Session: https://giving.paypallabs.com/authenticate/myaccount?token=HA-CYR26UHWRK8CS
Time: 17:58 - 18:10 (EU) 2012-08-13
Review: Your giving widgets - Account Index
