The Abandoned Cart Pro for WooCommerce plugin for WordPress is vulnerable to Authentication Bypass via Malleable Encryption and Bypassable HMAC in all versions up to, and including, 10.8.0

Overview

The Abandoned Cart Pro for WooCommerce plugin for WordPress is vulnerable to Authentication Bypass via Malleable Encryption and Bypassable HMAC in all versions up to, and including, 10.8.0. This is due to the use of MAC-free AES-CTR encryption for cart-recovery link tokens — where the 8-byte CTR nonce is carried inside the ciphertext blob and the encryption key is looked up using the attacker-supplied user_email GET parameter — combined with an HMAC nonce check in wcap_email_track_links() that is only enforced when the wcap_nonce parameter is non-empty, allowing complete bypass by omission, and an insecure direct object reference on the decrypted abandoned_id with no ownership verification confirming the cart belongs to the email used for decryption. This makes it possible for unauthenticated attackers who possess a single legitimate cart-recovery link (obtained from their own reminder email) to recover the keystream, forge a ciphertext that decrypts to any victim's cart ID, and trigger a call to wp_set_auth_cookie() for the victim user — achieving full account takeover of any user who has ever abandoned a cart, including administrators. The auto-login feature defaults to enabled and is forced on during plugin upgrades, meaning all affected installations are exploitable without any additional configuration.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.