The MStore API WordPress plugin before 4.21.0 does not correctly verify the cryptographic signature of the token used to authenticate its phone-based login, allowing unauthenticated attackers who know a registered user's phone number to forge a token and take over that user's account, including administrator accounts.

The MStore API WordPress plugin before 4.21.0 does not correctly verify the cryptographic signature of the token used to authenticate its phone-based login, allowing unauthenticated attackers who know a registered user's phone number to forge a token and take over that user's account, including administrator accounts.