Vulnerability Note VU#459446

osCommerce v2.3.1 with PayPal website payments standard module v1.0 design vulnerability

Original Release date: 18 Sep 2012 | Last revised: 15 May 2013


osCommerce 2.3.1 and possibly other versions with the PayPal website payments standard module is susceptible to a client-side attack that results in an attacker purchasing items without having to pay for them.


It has been reported that osCommerce 2.3.1 using the PayPal website payments standard module 1.0 contains a design flaw that allows an attacker to buy items without having to pay for them. The parameter for the merchant's PayPal email address is controlled on the client-side and not verified by the server. This allows an attacker to change the PayPal email address to one the attacker controls allowing the attacker to purchase items on a website but effectively pay themselves instead of the merchant. Manual verification of website orders with the PayPal transactions would need to be performed to detect this fraud.


An attacker can effectively purchase items without paying the merchant for them.


Apply an Update

osCommerce Online Merchant v2.3.4 and v1.1 of the payment module will be released to address this issue. If you are unable to update, please consider the following workaround.

Enable Encrypted Web Payments in the payment module configuration.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
osCommerceAffected18 Jul 201224 Aug 2012
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N
Temporal 4.0 E:POC/RL:U/RC:UC
Environmental 4.0 CDP:ND/TD:ND/CR:ND/IR:ND/AR:ND



Thanks to Giancarlo Pellegrino of SAP Research for reporting this vulnerability.

This document was written by Jared Allar.

Other Information

  • CVE IDs: CVE-2012-2991
  • Date Public: 17 Sep 2012
  • Date First Published: 18 Sep 2012
  • Date Last Updated: 15 May 2013
  • Document Revision: 22


If you have feedback, comments, or additional information about this vulnerability, please send us email.