In CEH’s Cloud Computing module, one of the most common real-world causes of cloud data exposure is misconfiguration, especially overly permissive network access controls. Cloud platforms commonly use constructs like security groups / firewall rules / network ACLs to define inbound and outbound access. CEH highlights that exposing sensitive services (databases, storage endpoints, admin panels) to the public internet—whether by “0.0.0.0/0” rules, overly broad ports, or unintended administrative access—frequently results in unauthorized access and data leakage even without sophisticated exploit chains.
Option D is therefore the most likely, because misconfigured security groups can directly expose customer data stores or management interfaces, enabling data theft through normal connectivity rather than exploiting a rare hypervisor flaw.
Option A (hypervisor side-channel attack) is advanced and less common; it typically requires high attacker capability and conditions not implied here. Option B (DoS) impacts availability, not confidentiality, so it doesn’t best explain data exposure. Option C (brute force passwords) is possible, but the question emphasizes an “unknown vulnerability” in the cloud environment—CEH teaching often frames “unknown vulnerability” in cloud incidents as misconfiguration or uncontrolled exposure rather than authentication guessing alone.
CEH countermeasures include least-privilege security group rules, segmentation, continuous configuration monitoring, cloud security posture management, and auditing publicly exposed resources.
