Exam 312-50v12 topic 1 question 241 discussion

During a penetration test, an ethical hacker is exploring the security of a complex web application. The application heavily relies on JavaScript for client-side input sanitization, with an apparent assumption that this alone is adequate to prevent injection attacks. During the investigation, the ethical hacker also notices that the application utilizes cookies to manage user sessions but does not enable the HttpOnly flag. This lack of flag potentially exposes the cookies to client-side scripts. Given these identified vulnerabilities, what would be the most effective strategy for the ethical hacker to exploit this application?