Insecure direct object reference (IDOR) vulnerability in Anapi Group's h6web, allows an authenticated attacker to access other users' information by making a POST request and modifying the “pkrelated” parameter in the “/h6web/ha_datos_hermano.php” endpoint to refer to another user. In addition, the first request could also allow the attacker to impersonate other users. As a result, all requests made after exploitation of the IDOR vulnerability will be executed with the privileges of the impersonated user.