Unauthenticated Broken Access Control in Simple Membership <= 4.7.8 versions.

The Simple Membership WordPress plugin before 4.7.8 does not sanitise a subscriber name value received from an unauthenticated payment approval request, nor escape it when displaying it in the administration dashboard, allowing unauthenticated attackers to store arbitrary JavaScript that executes in an administrator's session.

The Simple Membership WordPress plugin before 4.7.5 does not verify the authenticity of Stripe webhook requests when no signing secret is configured, nor escape a value taken from them before outputting it in an administrator notice, allowing unauthenticated attackers to inject arbitrary web scripts that execute in the context of a logged-in administrator.

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in wp.insider Simple Membership simple-membership allows Phishing.This issue affects Simple Membership: from n/a through <= 4.5.3.

Improper Privilege Management vulnerability in smp7, wp.Insider Simple Membership allows Privilege Escalation.This issue affects Simple Membership: from n/a through 4.3.4.

Improper Authentication vulnerability in smp7, wp.Insider Simple Membership.This issue affects Simple Membership: from n/a through 4.3.4.

The Simple Membership plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Display Name' parameter in all versions up to, and including, 4.4.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability requires social engineering to successfully exploit, and the impact would be very limited due to the attacker requiring a user to login as the user with the injected payload for execution.