A Directory Traversal attack, also known as path traversal, exploits weaknesses in how a web server or web application processes user-supplied file and directory paths through URLs or parameters. In CEH-aligned terminology, the attacker crafts requests that use traversal sequences such as dot-dot-slash patterns or encoded equivalents to escape the intended web root or permitted directory and reach sensitive locations on the underlying file system. The question states Sofia "manipulates resource paths" and successfully accesses
"restricted system files," revealing "sensitive configuration data." This is the defining outcome of directory traversal: unauthorized access to files that should never be directly retrievable via the web interface, including application configuration files, server configuration, environment files, or other OS-level resources.
The prompt also eliminates other options by describing what the issue is not. It is not header manipulation, which would be more consistent with HTTP response splitting or header injection behaviors. It is not cached content tampering, which points to web cache poisoning. It is not credential compromise, which would indicate password cracking. Instead, the root cause is explicitly "failure to validate input paths," matching CEH emphasis on inadequate input validation and improper path normalization or canonicalization before file access. Defensive guidance typically focuses on strict allowlisting of accessible resources, canonicalizing paths and enforcing a fixed base directory, blocking traversal tokens and their encoded forms, using indirect references instead of raw file paths, and applying least-privilege permissions to reduce impact if traversal is attempted.

A covert channel is a communication method used to transfer information in a way that violates security policy, often by repurposing legitimate protocols or functions for unauthorized communication.
From CEH v13 Official Courseware:
* Module 6: Malware Threats
* Topic: Covert Communication and Data Exfiltration Techniques
CEH v13 Study Guide states:
"A covert channel exploits unintended uses of legitimate communication protocols. It allows data to be transmitted without detection by hiding the communication inside seemingly benign traffic." Incorrect Options:
* A: A non-standard port may aid in hiding services, but doesn't constitute a covert channel.
* C: Multiplexing is a normal communication mechanism.
* D: WEP is insecure, but this isn't related to covert channels.
Reference:CEH v13 Study Guide - Module 6: Covert Communication ChannelsNIST SP 800-30 - Covert Channels in Security Models

According to CEH v13 Cloud Computing, backup integrity and resilience are critical components of cloud security. The 3-2-1 backup model is a widely recommended best practice to mitigate unauthorized access, data corruption, and ransomware-related incidents.
The 3-2-1 rule dictates that organizations should maintain:
3 copies of critical data
Stored on 2 different media types
With 1 copy stored offsite or offline
This approach ensures that even if one backup is compromised, altered, or deleted-as described in the scenario-clean and trusted versions of the data remain available for restoration. CEH v13 emphasizes that offline or immutable backups significantly reduce the impact of malicious modification.
Option A focuses on physical security, which does not protect cloud backups. Option B addresses availability, not integrity. Option C is relevant to web application security, not backup protection.
CEH v13 explicitly highlights backup segregation and redundancy as key countermeasures against cloud data compromise. Therefore, Option D is the most direct and effective mitigation strategy.

Blocking or disabling unnecessary ports, protocols, and services reduces the attack surface, preventing attackers from exploiting services like NetBIOS and SMB that are not required for the server's primary function.