Magento Commerce versions 2.4.2 (and earlier), 2.4.2-p1 (and earlier) and 2.3.7 (and earlier) are affected by an improper input validation vulnerability. An authenticated attacker can trigger an insecure direct object reference in the `V1/customers/me` endpoint to achieve information exposure and privilege escalation.
https://helpx.adobe.com/security/products/magento/apsb21-64.html