[FD] Saveya Bounty #1 - Bypass & Persistent Vulnerability

Document Title: =============== Saveya Bounty #1 - Bypass & Persistent Vulnerability References (Source): ==================== http://ift.tt/2amN3fR SaveYa ID: 56 Acknowledgements: http://ift.tt/2abTUYl Release Date: ============= 2016-07-26 Vulnerability Laboratory ID (VL-ID): ==================================== 1857 Common Vulnerability Scoring System: ==================================== 3.7 Product & Service Introduction: =============================== As one of the leading gift card exchanges, SaveYa passes along the savings to you by buying unwanted gift cards. In turn, gift cards from many popular retailers are sold at a discount, below face value, and you can save big time on your everyday or one time expenses. Browse or search our extensive list of discounted gift cards for today’s most popular retailers before you make that next big purchase. If you are a shopper on the go, you can download our discount gift card app to save even more instantly. Our one of a kind savings app alerts you before checkout in order to take advantage of potential savings by buying discounted gift cards. (Copy of the Vendor Homepage: https://www.saveya.com/ ) Abstract Advisory Information: ============================== The vulnerability laboratory core research team discovered an application-side input validation vulnerability and filter bypass issue in the Saveya web-application. Vulnerability Disclosure Timeline: ================================== 2016-06-15: Researcher Notification & Coordination (Benjamin Kunz Mejri) 2016-06-17 Vendor Notification (Saveya Security Team - Bug Bounty Program) 2016-06-18: Vendor Response/Feedback (Saveya Security Team - Bug Bounty Program) 2016-07-25: Vendor Fix/Patch (Saveya Site Service Developer Team) 2016-07-26: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Affected Product(s): ==================== Saveya Product: Saveya - Online Service (Web-Application) 2016 Q2 Exploitation Technique: ======================= Remote Severity Level: =============== Medium Technical Details & Description: ================================ An application-side input validation and mail encode web vulnerability has been discovered in the official Saveya online service web-application. The application-side vulnerability allows remote attacker to inject own malicious script codes to the application-side of the vulnerable module or function. The vulnerability is located in the `Firstname` and `Lastname` parameter values of the `./Register` module POST method request. Remote attackers are able to inject own malicious script codes to the application-side of the profile values. After the registration a confirm and verification email is send by the service with the firstname and lastname values in the message body. Thus values are wrong encoded and can execute persistent injected script codes. The security risk of the application-side mail encode web vulnerability is estimated as medium with a cvss (common vulnerability scoring system) count of 3.8. Exploitation of the persistent input validation web vulnerability requires no privileged web-application user account and low or medium user interaction. Successful exploitation of the vulnerability results in session hijacking, persistent phishing attacks, persistent external redirects to malicious source and persistent manipulation of affected or connected application modules. Request Method(s): [+] POST Vulnerable Module(s): [+] Register - Account Registration SaveYa Vulnerable Parameter(s): [+] Firstname [+] Lastname Affected Module(s): [+] Verify Email [+] Account Congratulation Email Proof of Concept (PoC): ======================= The persistent vulnerability can be exploited by remote attackers without privileged web-application user account and with low user interaction. For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue. Manual steps to reproduce the vulnerability ... 1. Open the Saveya website 2. Click to Signup module 3. The registration form opens 4. Inject random values and a target attack email to include via POST 5. Inject to the Firstname and Lastname input field values your own malicious script code 6. Save the request via POST submit 7. Check the inbox 8. First the email of the verify arrives and after that the email congratulation account to verify Note: In both emails the persistent injected script code executes in the message body context 9. Successful reproduce of the remote mail encode web vulnerability and input validation issue PoC #1: Welcome Email

Welcome "><"[PERSISTENT INJECTED SCRIPT CODE EXECUTE!]%20%20>" PoC #2: Congratulations Email Account

Congratulations "><"[PERSISTENT INJECTED SCRIPT CODE EXECUTE!]%20%20>" Source: Gmail -> IFTTT-> Blogger