The WPCOM Member plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.7.27 via the uuid and code parameters of the social-login callback handler registered on the init hook. The vulnerability exists because the login function's social-login flow performs no nonce validation, no OAuth state verification, and no per-visitor namespace isolation in the session store, allowing an unauthenticated attacker to issue a crafted GET request that writes an attacker-named, attacker-valued entry into the global session namespace (bypassing the per-visitor prefix by prepending an underscore), then issue a second GET request triggering weappnewuser() to read that forged entry and resolve the attacker-supplied openid value to a bound WordPress account before wpsetauthcookie() establishes a fully authenticated session. This makes it possible for unauthenticated attackers to log in as any WordPress user — including administrators — whose bound social provider identifier (openid/unionid) is known or discoverable. Successful exploitation requires that the target site has at least one social provider configured (which activates the vulnerable handler) and that the attacker knows or can enumerate the victim account's bound openid or unionid.

The WPCOM Member plugin for WordPress is vulnerable to time-based SQL Injection via the ‘userphone’ parameter in all versions up to, and including, 1.7.6 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Lomu WPCOM Member wpcom-member allows Reflected XSS.This issue affects WPCOM Member: from n/a through <= 1.5.4.

The WPCOM Member plugin for WordPress is vulnerable to privilege escalation in all versions up to, and including, 1.5.2.1. This is due to the plugin allowing arbitrary data to be passed to wpinsertuser() during registration. This makes it possible for unauthenticated attackers to update their role to that of an administrator during registration.