A remote code execution vulnerability exists within osCommerce Online Merchant version 2.3.4.1 due to insecure default configuration and missing authentication in the installer workflow. By default, the /install/ directory remains accessible after installation. An unauthenticated attacker can invoke install4.php, submit crafted POST data, and inject arbitrary PHP code into the configure.php file. When the application later includes this file, the injected payload is executed, resulting in full server-side compromise.

The PayPal (aka MODULEPAYMENTPAYPALSTANDARD) module before 1.1 in osCommerce Online Merchant before 2.3.4 allows remote attackers to set the payment recipient via a modified value of the merchant's e-mail address, as demonstrated by setting the recipient to one's self.

Cross-site scripting (XSS) vulnerability in osCommerce/OM/Core/Site/Shop/Application/Cart/pages/main.php in OSCommerce Online Merchant 3.0.2 allows remote attackers to inject arbitrary web script or HTML via the valuetitle parameter, as demonstrated using the "Front" field in the shirt module.

Cross-site scripting (XSS) vulnerability in osCommerce 2.2MS1J before R9, and osCommerce Online Merchant before 2.3.1, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Cross-site scripting (XSS) vulnerability in osCommerce/OM/Core/Site/Shop/Application/Checkout/pages/main.php in OSCommerce Online Merchant 3.0.2 allows remote attackers to inject arbitrary web script or HTML via the valuetitle parameter, a different vulnerability than CVE-2012-1059.