Title: ====== Paypal Core Bug Bounty #3 - Persistent Web Vulnerability Date: ===== 2012-12-12 References: =========== http://www.vulnerability-lab.com/get_content.php?id=635 VL-ID: ===== 635 Common Vulnerability Scoring System: ==================================== 4 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 4–9, 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 persistent web vulnerability in the official Paypal (core) ecommerce website content management system. Report-Timeline: ================ 2012-06-30: Researcher Notification & Coordination 2012-06-30: Vendor Notification 2012-07-02: Vendor Response/Feedback 1 2012-10-08: Vendor Response/Feedback 2 2012-12-11: Vendor Fix/Patch 2012-12-12: Public or Non-Public Disclosure Status: ======== Published Exploitation-Technique: ======================= Remote Affected Products: ================== Paypal - Core Application [2012 Q2-3] Severity: ========= Medium Details: ======== A persistent input validation vulnerability is detected in the official Paypal (core) ecommerce website content management system. The bug allows remote attackers to implement/inject own malicious script code on the application side (persistent). The persistent input validation vulnerability is located in the Adressbuch module with the bound vulnerable search function when processing to request script code tags as `Addressbuch` contacts. The code will be executed out of the search result listing web context. Remote exploitation requires low user interaction and a privileged paypal banking application user account. Successful exploitation of the vulnerability results in persistent session hijacking (admin), account steal via persistent phishing or persistent search module web context manipulation. Vulnerable Module(s): [+] Adressbuch > Search > Benutzer/Kontakt Vulnerable Parameter(s): [+] search_str - Results Affected Section(s): [+] Results - Index (Listing) Proof of Concept: ================= The persistent vulnerability can be exploited by remote attackers with privileged paypal user account and low required user interaction. For demonstration or reproduce ... PoC: [Existing Listing] (Index) Adressbuch > Search > Benutzer/Kontakt > results
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Note: The name with the code was saved in the addressbook. Only the matching and successful result leads to the persistent execution of the web context. When the other user is searching the existing account of the addressbook the code will be executed persistent out of the matching search result web context listing. If you do not know this it will be a bit harder to reproduce. The bug is 100% existing because the screenshots show it and also the poc. I found the issue by manually exploitation over the different application layers and function. Maybe i guessed to implement this details to the submission. The requested code with the malicious persistent code can be reviewed in the attached poc document. Manually reproduce ... 1. Go to the addressbook and switch to add a new contact to adressbook 2. Include script code (html/js) as username to the addressbook and save the context 2. Now, switch to the user search (addressbook) module (other layer) & click the user contact search to activate 3. Include the exact name of the username (script code (html/js)) from the addressbook and press the search button 4. The context of the other layer from the addressbook will be executed directly out of the results listing page of the exisiting user contacts 5. Done! POST REQUEST: method="post" name="searchContact" Solution: ========= The vulnerability can be patched by parsing the addressbook search results module with the bound vulnerability matching account listing. Risk: ===== The security risk of the persistent script code inject vulnerability is estimated as medium(+). Credits: ======== Vulnerability Laboratory [Research Team] - Benjamin Kunz Mejri (bkm@vulnerability-lab.com) Disclaimer: =========== The information provided in this advisory is provided as it is without any warranty. Vulnerability-Lab disclaims all warranties, either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability- Lab or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. We do not approve or encourage anybody to break any vendor licenses, policies, deface websites, hack into databases or trade with fraud/stolen material. Domains: www.vulnerability-lab.com - www.vuln-lab.com - www.vulnerability-lab.com/register Contact: admin@vulnerability-lab.com - support@vulnerability-lab.com - research@vulnerability-lab.com Section: video.vulnerability-lab.com - forum.vulnerability-lab.com - news.vulnerability-lab.com Social: twitter.com/#!/vuln_lab - facebook.com/VulnerabilityLab - youtube.com/user/vulnerability0lab Feeds: vulnerability-lab.com/rss/rss.php - vulnerability-lab.com/rss/rss_upcoming.php - vulnerability-lab.com/rss/rss_news.php Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability Laboratory. Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other media, are reserved by Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, sourcecode, videos and other information on this website is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), modify, use or edit our material contact (admin@vulnerability-lab.com or support@vulnerability-lab.com) to get a permission. Copyright © 2012 | Vulnerability Laboratory -- VULNERABILITY RESEARCH LABORATORY LABORATORY RESEARCH TEAM CONTACT: research@vulnerability-lab.com