Paid Memberships Pro <= 2.12.3 - Authenticated (Subscriber+) Arbitrary File Upload

The Paid Memberships Pro plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation in the 'pmpro_paypalexpress_session_vars_for_user_fields' function in versions up to, and including, 2.12.3. This makes it possible for authenticated attackers with subscriber privileges or above, to upload arbitrary files on the affected site's server which may make remote code execution possible. This can be exploited if 2Checkout (deprecated since version 2.6) or PayPal Express is set as the payment method and a custom user field is added that is only visible at profile, and not visible at checkout according to its settings.

An attacker needs Subscriber access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Paid Memberships Pro 2.12.4 closes this, and updating the plugin is the step that ends it.

• Firewall
• Scanner
• Alerts