Pass the ECCouncil CEH v13 312-50v13 Questions and answers with ExamsMirror

This is a classic example of Web Parameter Tampering. This occurs when attackers manipulate parameters exchanged between client and server to exploit vulnerabilities in the application logic. In this case:

Damount and Camount are passed via URL parameters.

The web application is not validating or sanitizing the values.

Altering the values affects the transaction outcome.

This is not an SQL Injection (no SQL code shown), nor is it XSS (no script injection), and it is unrelated to Cookie Tampering (which involves browser-stored cookies).

Comprehensive and Detailed Explanation:

The correct file name is /var/log/auth.log (not auth.fesg). “auth.fesg” is a typo or does not exist by default in Linux systems.

Linux login records include:

/var/log/auth.log – authentication logs

/var/log/wtmp – records login sessions

/var/log/btmp – records failed logins

/var/log/user.log – logs user-level messages (optional)

Therefore, B is not a valid log file.

From CEH v13 Courseware:

Module 6: System Hacking → Covering Tracks in Linux

This form of testing is known as Fuzzing. Fuzzing (or fuzz testing) is an automated software testing technique that involves providing invalid, unexpected, or random data as inputs to a computer program. The program is then monitored for exceptions such as crashes, failing built-in code assertions, or potential memory leaks.

In the CEH v13 courseware and study guide:

Module 6: Malware Threats

Subsection: Malware Analysis and Reverse Engineering Techniques

CEH v13 Official Study Guide and iLabs Practical

The CEH v13 guide states:

“Fuzzing is used as a software testing technique that involves sending malformed or unexpected inputs to an application in order to detect vulnerabilities such as buffer overflows, crashes, or unexpected behavior. It is particularly useful during vulnerability assessments and exploit development.”

Thus, Fuzzing helps identify vulnerabilities due to improper input validation and is widely used in vulnerability discovery and exploit testing.

Incorrect Options:

A. Randomizing: Not a recognized security testing method.

B. Bounding: Refers to setting limits or constraints; not relevant here.

C. Mutating: Can be part of fuzzing (mutation-based fuzzing), but not the umbrella term.

https://en.wikipedia.org/wiki/RADIUS

Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized authentication, authorization, and accounting (AAA) management for users who connect and use a network service.

RADIUS is a client/server protocol that runs in the application layer, and can use either TCP or UDP. Network access servers, which control access to a network, usually contain a RADIUS client component that communicates with the RADIUS server. RADIUS is often the back-end of choice for 802.1X authentication. A RADIUS server is usually a background process running on UNIX or Microsoft Windows.

Authentication and authorization

The user or machine sends a request to a Network Access Server (NAS) to gain access to a particular network resource using access credentials. The credentials are passed to the NAS device via the link-layer protocol—for example, Point-to-Point Protocol (PPP) in the case of many dialup or DSL providers or posted in an HTTPS secure web form.

In turn, the NAS sends a RADIUS Access Request message to the RADIUS server, requesting authorization to grant access via the RADIUS protocol.

This request includes access credentials, typically in the form of username and password or security certificate provided by the user. Additionally, the request may contain other information which the NAS knows about the user, such as its network address or phone number, and information regarding the user's physical point of attachment to the NAS.

The RADIUS server checks that the information is correct using authentication schemes such as PAP, CHAP or EAP. The user's proof of identification is verified, along with, optionally, other information related to the request, such as the user's network address or phone number, account status, and specific network service access privileges. Historically, RADIUS servers checked the user's information against a locally stored flat-file database. Modern RADIUS servers can do this or can refer to external sources—commonly SQL, Kerberos, LDAP, or Active Directory servers—to verify the user's credentials.

The RADIUS server then returns one of three responses to the NAS:

1) Access-Reject,

2) Access-Challenge,

3) Access-Accept.

Access-Reject

The user is unconditionally denied access to all requested network resources. Reasons may include failure to provide proof of identification or an unknown or inactive user account.

Access-Challenge

Requests additional information from the user such as a secondary password, PIN, token, or card. Access-Challenge is also used in more complex authentication dialogs where a secure tunnel is established between the user machine and the Radius Server in a way that the access credentials are hidden from the NAS.

Access-Accept

The user is granted access. Once the user is authenticated, the RADIUS server will often check that the user is authorized to use the network service requested. A given user may be allowed to use a company's wireless network, but not its VPN service, for example. Again, this information may be stored locally on the RADIUS server or may be looked up in an external source such as LDAP or Active Directory.

The Security Account Manager (SAM) file on Windows contains user account information, including password hashes. Hackers target this file to extract credentials for offline cracking using tools like L0phtCrack or Cain & Abel.

From CEH v13 Official Courseware:

Module 6: Malware Threats

Module 4: Enumeration

CEH v13 Study Guide states:

“The SAM file stores hashed user credentials. If attackers gain access to it, they can extract password hashes and perform brute-force or dictionary attacks offline.”

Common locations:

C:\Windows\System32\config\SAM

C:\Windows\Repair\SAM

In CEH v13 Module 14: Cryptography, Serpent is detailed as one of the finalists in the Advanced Encryption Standard (AES) competition, known for its strong security characteristics.

Key Features of Serpent:

128-bit block size, and key sizes of 128, 192, or 256 bits.

Uses 32 rounds of substitution and permutation.

Operates on four 32-bit words per block.

Employs 8 different S-boxes, each with a 4-bit input and 4-bit output.

Designed to provide high security and resistance against differential cryptanalysis.

Option Clarification:

A. TEA: Uses a Feistel structure with simple operations, but not 32 rounds with S-boxes.

B. CAST-128: Has 64-bit block size and fewer rounds.

C. RC5: Variable block and key sizes but doesn’t use 32 rounds with fixed S-box design.

D. Serpent: Matches all given features.

CHNTPW (Change NT Password) is a Linux-based utility that allows attackers or administrators to:

Reset Windows user account passwords

Unlock disabled or locked user accounts

Remove password protection without knowing the original password

It works by editing the Windows SAM (Security Account Manager) file located in the Windows system directory.

Reference – CEH v13 Official Study Guide:

Module 5: System Hacking

Quote:

“CHNTPW is a tool that can reset or change passwords on Windows systems by directly editing the SAM database. It is commonly run from a Linux LiveCD.”

Incorrect Options:

A. John the Ripper is for cracking passwords, not resetting them directly.

B. SET (Social Engineering Toolkit) is for phishing and payloads, not password resets.

D. Cain & Abel is a password recovery tool for Windows but runs on Windows, not Linux.

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In this attack KRACK is an acronym for Key Reinstallation Attack. KRACK may be a severe replay attack on Wi-Fi Protected Access protocol (WPA2), which secures your Wi-Fi connection. Hackers use KRACK to take advantage of a vulnerability in WPA2. When in close range of a possible victim, attackers can access and skim encrypted data using KRACK.

How KRACK Works

Your Wi-Fi client uses a four-way handshake when attempting to attach to a protected network. The handshake confirms that both the client — your smartphone, laptop, et cetera — and therefore the access point share the right credentials, usually a password for the network. This establishes the Pairwise passkey (PMK), which allows for encoding .

Overall, this handshake procedure allows for quick logins and connections and sets up a replacement encryption key with each connection. this is often what keeps data secure on Wi-Fi connections, and every one protected Wi-Fi connections use the four-way handshake for security. This protocol is that the reason users are encouraged to use private or credential-protected Wi-Fi instead of public connections.

KRACK affects the third step of the handshake, allowing the attacker to control and replay the WPA2 encryption key to trick it into installing a key already in use. When the key’s reinstalled, other parameters related to it — the incremental transmit packet number called the nonce and therefore the replay counter — are set to their original values.

Rather than move to the fourth step within the four-way handshake, nonce resets still replay transmissions of the third step. This sets up the encryption protocol for attack, and counting on how the attackers replay the third-step transmissions, they will take down Wi-Fi security.

Why KRACK may be a Threat

Think of all the devices you employ that believe Wi-Fi. it isn’t almost laptops and smartphones; numerous smart devices now structure the web of Things (IoT). due to the vulnerability in WPA2, everything connected to Wi-Fi is in danger of being hacked or hijacked.

Attackers using KRACK can gain access to usernames and passwords also as data stored on devices. Hackers can read emails and consider photos of transmitted data then use that information to blackmail users or sell it on the Dark Web.

Theft of stored data requires more steps, like an HTTP content injection to load malware into the system. Hackers could conceivably take hold of any device used thereon Wi-Fi connection. Because the attacks require hackers to be on the brink of the target, these internet security threats could also cause physical security threats.

On the opposite hand, the necessity to be in close proximity is that the only excellent news associated with KRACK, as meaning a widespread attack would be extremely difficult.

Victims are specifically targeted. However, there are concerns that a experienced attacker could develop the talents to use HTTP content injection to load malware onto websites to make a more widespread affect.

Everyone is in danger from KRACK vulnerability. Patches are available for Windows and iOS devices, but a released patch for Android devices is currently in question (November 2017). There are issues with the discharge , and lots of question if all versions and devices are covered.

The real problem is with routers and IoT devices. These devices aren’t updated as regularly as computer operating systems, and for several devices, security flaws got to be addressed on the manufacturing side. New devices should address KRACK, but the devices you have already got in your home probably aren’t protected.

The best protection against KRACK is to make sure any device connected to Wi-Fi is patched and updated with the newest firmware. that has checking together with your router’s manufacturer periodically to ascertain if patches are available.

The safest connection option may be a private VPN, especially when publicly spaces. If you would like a VPN for private use, avoid free options, as they need their own security problems and there’ll even be issues with HTTPs. Use a paid service offered by a trusted vendor like Kaspersky. Also, more modern networks use WPA3 for better security.

Avoid using public Wi-Fi, albeit it’s password protection. That password is out there to almost anyone, which reduces the safety level considerably.

All the widespread implications of KRACK and therefore the WPA2 vulnerability aren’t yet clear. what’s certain is that everybody who uses Wi-Fi is in danger and wishes to require precautions to guard their data and devices.

Banner grabbing is a technique wont to gain info about a computer system on a network and the services running on its open ports. administrators will use this to take inventory of the systems and services on their network. However, an to find will use banner grabbing so as to search out network hosts that are running versions of applications and operating systems with known exploits.

Some samples of service ports used for banner grabbing are those used by Hyper Text Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP); ports 80, 21, and 25 severally. Tools normally used to perform banner grabbing are Telnet, nmap and Netcat.

For example, one may establish a connection to a target internet server using Netcat, then send an HTTP request. The response can usually contain info about the service running on the host:

This information may be used by an administrator to catalog this system, or by an intruder to narrow down a list of applicable exploits.

To prevent this, network administrators should restrict access to services on their networks and shut down unused or unnecessary services running on network hosts. Shodan is a search engine for banners grabbed from portscanning the Internet.

According to CEH v13 Module 08: Sniffing, the attack described is a classic example of ARP spoofing/poisoning which leads to Man-in-the-Middle (MITM) scenarios. In such attacks, a malicious actor sends forged ARP responses to associate their MAC address with the IP address of a target system, redirecting traffic through their machine.

Tool Used: BetterCAP

BetterCAP is a powerful, modular MITM framework.

It can:

Perform ARP spoofing

Intercept and manipulate HTTP/HTTPS traffic

Modify packets in real-time

Carry out credential harvesting and session hijacking

Miley's actions match the default behavior of BetterCAP during an ARP spoofing attack:

Spoof ARP to redirect traffic.

Intercept and analyze (or manipulate) traffic.

Option Clarification:

A. Gobbler: An older ARP tool, but mostly for ARP scanning, not modern MITM attacks.

B. KDerpNSpoof: Incorrect or misspelled; not a recognized CEH tool.

C. BetterCAP: Correct – used for ARP spoofing and traffic manipulation.

D. Wireshark: Passive sniffer; cannot perform ARP spoofing or MITM.

A Ping of Death attack is a type of DoS attack that exploits a vulnerability in the IP protocol that allows packets to be fragmented and reassembled at the destination. The attacker sends a malformed packet that exceeds the maximum size of 65,535 bytes, which causes the target system to crash or become unstable when it tries to reassemble the packet. This attack can affect various operating systems and devices, such as routers, switches, and firewalls. A Ping of Death attack can be detected by monitoring the network traffic for unusually large packets or ICMP messages. References:

Ping of Death (PoD) Attack

Denial-of-Service Attacks: History, Techniques & Prevention

What is a denial-of-service (DoS) attack?

Brute-force attack when an attacker uses a set of predefined values to attack a target and analyze the response until he succeeds. Success depends on the set of predefined values. It will take more time if it is larger, but there is a better probability of success. In a traditional brute-force attack, the passcode or password is incrementally increased by one letter/number each time until the right passcode/password is found.

Implementing regular firmware updates for all IoT devices is the primary recommendation to prevent DDoS attacks on the smart city project. Firmware updates can fix security vulnerabilities, patch bugs, and improve performance of the IoT devices, making them less susceptible to malware infections and botnet recruitment12. Firmware updates can also enable new security features, such as encryption, authentication, and firewall, that can protect the IoT devices from unauthorized access and data theft3. Firmware updates should be done automatically or remotely, without requiring user intervention, to ensure timely and consistent security across the IoT network4.

The other options are not as effective or feasible as firmware updates for the following reasons:

B. Deploying network intrusion detection systems (IDS) across the IoT network can help detect and alert DDoS attacks, but not prevent them. IDS can monitor network traffic and identify malicious patterns, such as high volume, spoofed IP addresses, or unusual protocols, that indicate a DDoS attack5. However, IDS cannot block or mitigate the attack, and may even be overwhelmed by the flood of traffic, resulting in false positives or missed alerts. Moreover, deploying IDS across a vast network of IoT devices can be costly, complex, and resource-intensive, as it requires dedicated hardware, software, and personnel.

C. Establishing strong, unique passwords for each IoT device can prevent unauthorized access and brute-force attacks, but not DDoS attacks. Passwords can protect the IoT devices from being compromised by hackers who try to guess or crack the default or weak credentials. However, passwords cannot prevent DDoS attacks that exploit known or unknown vulnerabilities in the IoT devices, such as buffer overflows, command injections, or protocol flaws. Moreover, establishing and managing strong, unique passwords for each IoT device can be challenging and impractical, as it requires user awareness, memory, and effort.

D. Implementing IP address whitelisting for all IoT devices can restrict network access and communication to trusted sources, but not DDoS attacks. IP address whitelisting can filter out unwanted or malicious traffic by allowing only the predefined IP addresses to connect to the IoT devices. However, IP address whitelisting cannot prevent DDoS attacks that use spoofed or legitimate IP addresses, such as reflection or amplification attacks, that bypass the whitelisting rules. Moreover, implementing IP address whitelisting for all IoT devices can be difficult and risky, as it requires constant updating, testing, and monitoring of the whitelist, and may block legitimate or emergency traffic by mistake.

A dictionary Attack as an attack vector utilized by the attacker to break in a very system, that is password protected, by golf shot technically each word in a very dictionary as a variety of password for that system. This attack vector could be a variety of Brute Force Attack.

The lexicon will contain words from an English dictionary and conjointly some leaked list of commonly used passwords and once combined with common character substitution with numbers, will generally be terribly effective and quick.

How is it done?

Basically, it’s attempting each single word that’s already ready. it’s done victimization machine-controlled tools that strive all the possible words within the dictionary.

Some password Cracking Software:

• John the ripper

• L0phtCrack

• Aircrack-ng

In CEH v13 Module 11: Hacking Wireless Networks, it is explained that disabling SSID broadcast only hides the SSID from casual scanning, not from determined attackers.

When a legitimate client connects to a hidden SSID, the SSID is included in the probe request and association packets, which can be easily sniffed using tools like Wireshark or Kismet.

Leaving authentication open adds no real protection.

Attackers can still capture traffic and use it to determine the SSID and connect to the access point.