If UserInfoServlet is exposed, it allows to bruteforce credentials. You can get valid usernames from jcr:createdBy, jcr:lastModifiedBy, cq:LastModifiedBy attributes of any JCR node.
AEM - Adobe Experience Manager is an enterprise-grade CMS. AEM is widely used by high-profile companies. AEM is big and complex. AEM also has 26 known CVEs. Misconfigured AEM applications can cause many critical vulnerabilities.
Access restriction should be applied.