312-50v13 Exam Dumps - Certified Ethical Hacker Exam (CEHv13)

One of the most important actions to secure a web server from common threats is to regularly update and patch the server software. This includes the operating system, the web server software, the database software, and any other applications or frameworks that run on the server. Updating and patching the server software can fix known vulnerabilities, bugs, or errors that could be exploited by attackers to compromise the server or the website. Failing to update and patch the server software can expose the server to common attacks, such as SQL injection, cross-site scripting, remote code execution, denial-of-service, etc.

Installing a web application firewall, limiting the number of concurrent connections to the server, and encrypting the company’s website with SSL/TLS are also good practices to secure a web server, but they are not as critical as updating and patching the server software. A web application firewall can filter and block malicious requests, but it cannot prevent attacks that exploit unpatched vulnerabilities in the server software. Limiting the number of concurrent connections to the server can prevent overload and improve performance, but it cannot stop attackers from sending malicious requests or payloads. Encrypting the company’s website with SSL/TLS can protect the data in transit between the server and the client, but it cannot protect the data at rest on the server or prevent attacks that target the server itself.

Therefore, the priority action to secure a web server from common threats is to regularly update and patch the server software.

Comprehensive and Detailed Explanation:

A TCP SYN flood is a type of Denial of Service (DoS) attack. The attacker sends a barrage of SYN packets with spoofed (random or unreachable) source IP addresses. The victim server replies with SYN/ACK, but the final ACK never arrives.

This results in:

The victim keeping the half-open connections in the queue.

The queue filling up, leading to new, legitimate requests being dropped.

From CEH v13 Courseware:

Module 9: Denial-of-Service Attacks → TCP SYN Flood

In CEH v13 Module 06: Malware Threats, stealth viruses are covered as advanced malware that can evade detection by:

Intercepting system calls related to file access.

Masking their presence in files, memory, or on disk.

Restoring original code temporarily to fool signature-based scanners.

These capabilities allow stealth viruses to:

Avoid detection by antivirus scanners.

Operate undisturbed until triggered.

Option Clarification:

A. Cavity virus: Hides in unused file space but doesn't evade as effectively.

C. File-extension virus: Exploits deceptive file names but is often detected.

D. Macro virus: Targets office documents, not highly evasive.

Correct answer is B. Stealth virus.

The most effective evasion technique to bypass the IDS signature detection while performing a SQL Injection attack is to leverage string concatenation to break identifiable keywords. This technique involves splitting SQL keywords or operators into smaller parts and joining them with string concatenation operators, such as ‘+’ or ‘||’. This way, the SQL query can still be executed by the database engine, but the IDS cannot recognize the keywords or operators as malicious, as they are hidden within strings. For example, the hacker could replace the keyword ‘OR’ with ‘O’||‘R’ or ‘O’+‘R’ in the SQL query, and the IDS would not be able to match the signature of a typical SQL injection pattern12.

The other options are not as effective as option D for the following reasons:

A. Implement case variation by altering the case of SQL statements: This option is not effective because most SQL engines and IDS systems are case-insensitive, meaning that they treat SQL keywords and operators the same regardless of their case. Therefore, altering the case of SQL statements would not help evade the IDS signature detection, as the IDS would still be able to match the signature of a typical SQL injection pattern3.

B. Employ IP fragmentation to obscure the attack payload: This option is not applicable because IP fragmentation is a network-level technique that splits IP packets into smaller fragments to fit the maximum transmission unit (MTU) of the network. IP fragmentation does not affect the content or structure of the SQL query, and it does not help evade the IDS signature detection, as the IDS would still be able to reassemble the fragments and match the signature of a typical SQL injection pattern4.

C. Use Hex encoding to represent the SQL query string: This option is not feasible because Hex encoding is a method of representing binary data in hexadecimal format, such as ‘0x41’ for ‘A’. Hex encoding does not work for SQL queries, as the SQL engine would not be able to interpret the hexadecimal values as valid SQL syntax. Moreover, Hex encoding would not help evade the IDS signature detection, as the IDS would still be able to decode the hexadecimal values and match the signature of a typical SQL injection pattern.

According to CEH v13 Module 04: Enumeration and Module 08: Sniffing, packet sniffers such as Wireshark, tcpdump, and EtherApe are designed to capture and analyze network traffic at the data link (Layer 2) and network (Layer 3) layers of the OSI model.

At Layer 2 (Data Link), sniffers capture Ethernet frames, including MAC addresses and frame type.

At Layer 3 (Network), sniffers interpret IP headers, IP addresses, and transport layer protocols (TCP, UDP).

They do not operate at Layer 1 (Physical) as they do not deal with raw electrical signals.

Packet sniffers also do not manipulate traffic but passively monitor and capture packets that traverse the network.

Therefore, the correct statement is:

Packet Sniffers operate on both Layer 2 & Layer 3 of the OSI model.

Option Analysis:

A. Layer 1: ❌ Incorrect. Layer 1 is the physical layer (electrical, optical signals).

B. Layer 2: ❌ Partially correct but incomplete.

C. Both Layer 2 & Layer 3: Correct. Full coverage of packet sniffing capabilities.

D. Layer 3: ❌ Partially correct but incomplete.

Reference from CEH v13 Courseware:

Module 08 – Sniffing, Section: How Packet Sniffers Work

CEH iLabs: Capturing Ethernet Frames and IP Packets Using Wireshark

OSI Model Mapping in CEH Official eBook

In CEH v13 Module 01: Introduction to Ethical Hacking, the types of law applicable to cybersecurity incidents are discussed. When executives fail to protect their company’s information systems and this leads to financial loss, data breaches, or negligence, the resulting liability is considered under civil law.

Civil law deals with non-criminal disputes such as negligence, liability, and contractual breaches.

A company or affected party may file a civil lawsuit for damages.

Executives can be held civilly liable for failing in their duty of care, especially when regulations like GDPR, SOX, or HIPAA are involved.

Two-factor Authentication or 2FA is a user identity verification method, where two of the three possible authentication factors are combined to grant access to a website or application.1) something the user knows, 2) something the user has, or 3) something the user is.

The possible factors of authentication are:

· Something the User Knows:

This is often a password, passphrase, PIN, or secret question. To satisfy this authentication challenge, the user must provide information that matches the answers previously provided to the organization by that user, such as “Name the town in which you were born.”

· Something the User Has:

This involves entering a one-time password generated by a hardware authenticator. Users carry around an authentication device that will generate a one-time password on command. Users then authenticate by providing this code to the organization. Today, many organizations offer software authenticators that can be installed on the user’s mobile device.

· Something the User Is:

This third authentication factor requires the user to authenticate using biometric data. This can include fingerprint scans, facial scans, behavioral biometrics, and more.

For example: In internet security, the most used factors of authentication are:

something the user has (e.g., a bank card) and something the user knows (e.g., a PIN code). This is two-factor authentication. Two-factor authentication is also sometimes referred to as strong authentication, Two-Step Verification, or 2FA.

The key difference between Multi-Factor Authentication (MFA) and Two-Factor Authentication (2FA) is that, as the term implies, Two-Factor Authentication utilizes a combination of two out of three possible authentication factors. In contrast, Multi-Factor Authentication could utilize two or more of these authentication factors.