The best answer is B. Cryptographic Failures because the scenario centers on weak protection of sensitive data in transit, enabling an attacker to intercept and manipulate the information. In CEH-aligned web and application security concepts (and consistent with modern web risk categories), cryptographic failures occur when an application does not properly use cryptography or secure transport protections to ensure confidentiality and integrity of sensitive data. If transport encryption is missing, weak, or incorrectly configured, attackers can perform man-in-the-middle style interception, tamper with traffic, steal session material, and exfiltrate regulated data—leading to outcomes like identity theft and payment card fraud, exactly as described.

The references to cookie snooping and downgrade attacks further reinforce this. Cookie snooping is commonly associated with session cookies being exposed due to insecure transport (for example, lack of HTTPS, mixed content, or cookies missing secure attributes), allowing an attacker on the network path to capture session identifiers and hijack accounts. Downgrade attacks occur when an attacker forces a connection to use weaker security settings (such as older TLS versions or insecure cipher suites) or coerces a fallback from HTTPS to HTTP when protections like HSTS are absent or misapplied. Both issues are tightly linked to improper cryptographic configuration and transport-layer security weaknesses.

Why the other options are not the best match: Broken Access Control concerns authorization—what users are allowed to access—not interception/manipulation of traffic. Identification and Authentication Failures focus on login/session identity mechanisms (passwords, MFA, session handling) but the key failure here is the weakness of cryptographic protection for data in transit. Security Misconfiguration can be a contributing cause (e.g., misconfigured TLS), but the question emphasizes the resulting weakness category—insufficient cryptographic/transport protections—making Cryptographic Failures the most precise answer.

Therefore, MediVault’s exposure to interception, manipulation, cookie snooping, and downgrade attacks most clearly indicates Cryptographic Failures.