Paypal Bug Bounty #21 - Persistent Encoding Vulnerability
Vulnerability Laboratory ID (VL-ID):
Common Vulnerability Scoring System:
Product & Service 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
(Copy of the Homepage: www.paypal.com) [http://en.wikipedia.org/wiki/PayPal]
Abstract Advisory Information:
The Vulnerability Laboratory Research Team discovered a Web Vulnerability in the official Paypal Plaza website application.
Vulnerability Disclosure Timeline:
2012-08-14: Researcher Notification & Coordination
2012-08-14: Vendor Notification
2012-08-16: Vendor Response/Feedback
2012-10-29: Vendor Fix/Patch by PayPal Inc
2012-11-25: Public or Non-Public Disclosure
Technical Details & Description:
A persistent input validation vulnerability is detected in the official Paypal Plaza website application (Customers).
The bug allows an attacker (remote) to implement/inject malicious script code on the application-side (persistent) of the paypal plaza
egreetings web service. The vulnerability is located in the (Step 5 Preview) eGreeting module notification with the bound vulnerable
your name and recipient’s name parameters. The vulnerability can be exploited by remote attackers with low or medium required user inter
action and without privileged Customer/Pro/Seller account. Successful exploitation of the vulnerability can lead to session hijacking (customers),
account steal via persistent web attacks, persistent phishing or stable (persistent) mail notification context manipulation.
[+] eGreetings Service
[+] Paypal Plaza (paypal-plaza.com)
[+] Step 5 Preview for eGreeting
[+] Your Name
[+] Recipient’s Name
[+] Notification Mail - Dear > [value]
Proof of Concept (PoC):
The persistent input validation vulnerability can be exploited by remote attackers with low or medium required user inter action.
For demonstration or reproduce ...
Review: Notification Mail - eGreetings Card Notification
You have received a eCard from your loved one.
You have received a eCard from your loved one.