CISSP Exam Dumps - Certified Information Systems Security Professional (CISSP)

The person in the organization who is accountable for the classification of data information assets is the data owner. The data owner is the person or entity that has the authority and responsibility for the creation, collection, processing, and disposal of a set of data. The data owner is also responsible for defining the purpose, value, and classification of the data, as well as the security requirements and controls for the data. The data owner should be able to determine the impact of the data on the mission of the organization, which means assessing the potential consequences of losing, compromising, or disclosing the data. The impact of the data on the mission of the organization is one of the main criteria for data classification, which helps to establish the appropriate level of protection and handling for the data. The data owner should also ensure that the data is properly labeled, stored, accessed, shared, and destroyed according to the data classification policy and procedures.

The other options are not the persons in the organization who are accountable for the classification of data information assets, but rather persons who have other roles or functions related to data management. The data architect is the person or entity that designs and models the structure, format, and relationships of the data, as well as the data standards, specifications, and lifecycle. The data architect supports the data owner by providing technical guidance and expertise on the data architecture and quality. The Chief Information Security Officer (CISO) is the person or entity that oversees the security strategy, policies, and programs of the organization, as well as the security performance and incidents. The CISO supports the data owner by providing security leadership and governance, as well as ensuring the compliance and alignment of the data security with the organizational objectives and regulations. The Chief Information Officer (CIO) is the person or entity that manages the information technology (IT) resources and services of the organization, as well as the IT strategy and innovation. The CIO supports the data owner by providing IT management and direction, as well as ensuring the availability, reliability, and scalability of the IT infrastructure and applications.

The security service that is served by the process of encrypting plaintext with the sender’s private key and decrypting ciphertext with the sender’s public key is identification. Identification is the process of verifying the identity of a person or entity that claims to be who or what it is. Identification can be achieved by using public key cryptography and digital signatures, which are based on the process of encrypting plaintext with the sender’s private key and decrypting ciphertext with the sender’s public key. This process works as follows:

• The sender has a pair of public and private keys, and the public key is shared with the receiver in advance.
• The sender encrypts the plaintext message with its private key, which produces a ciphertext that is also a digital signature of the message.
• The sender sends the ciphertext to the receiver, along with the plaintext message or a hash of the message.
• The receiver decrypts the ciphertext with the sender’s public key, which produces the same plaintext message or hash of the message.
• The receiver compares the decrypted message or hash with the original message or hash, and verifies the identity of the sender if they match.

The process of encrypting plaintext with the sender’s private key and decrypting ciphertext with the sender’s public key serves identification because it ensures that only the sender can produce a valid ciphertext that can be decrypted by the receiver, and that the receiver can verify the sender’s identity by using the sender’s public key. This process also provides non-repudiation, which means that the sender cannot deny sending the message or the receiver cannot deny receiving the message, as the ciphertext serves as a proof of origin and delivery.

The other options are not the security services that are served by the process of encrypting plaintext with the sender’s private key and decrypting ciphertext with the sender’s public key. Confidentiality is the process of ensuring that the message is only readable by the intended parties, and it is achieved by encrypting plaintext with the receiver’s public key and decrypting ciphertext with the receiver’s private key. Integrity is the process of ensuring that the message is not modified or corrupted during transmission, and it is achieved by using hash functions and message authentication codes. Availability is the process of ensuring that the message is accessible and usable by the authorized parties, and it is achieved by using redundancy, backup, and recovery mechanisms.

 The purpose of an Internet Protocol (IP) spoofing attack is to convince a system that it is communicating with a known entity. IP spoofing is a technique that involves creating and sending IP packets with a forged source IP address, which is usually the IP address of a trusted or authorized host. IP spoofing can be used for various malicious purposes, such as:

• Bypassing IP-based access control lists (ACLs) or firewalls that filter traffic based on the source IP address.
• Launching denial-of-service (DoS) or distributed denial-of-service (DDoS) attacks by flooding a target system with spoofed packets, or by reflecting or amplifying the traffic from intermediate systems.
• Hijacking or intercepting a TCP session by predicting or guessing the sequence numbers and sending spoofed packets to the legitimate parties.
• Gaining unauthorized access to a system or network by impersonating a trusted or authorized host and exploiting its privileges or credentials.

The purpose of IP spoofing is to convince a system that it is communicating with a known entity, because it allows the attacker to evade detection, avoid responsibility, and exploit trust relationships.

The other options are not the main purposes of IP spoofing, but rather the possible consequences or methods of IP spoofing. To send excessive amounts of data to a process, making it unpredictable is a possible consequence of IP spoofing, as it can cause a DoS or DDoS attack. To intercept network traffic without authorization is a possible method of IP spoofing, as it can be used to hijack or intercept a TCP session. To disguise the destination address from a target’s IP filtering devices is not a valid option, as IP spoofing involves forging the source address, not the destination address.

 Implementing logical network segmentation at the switches is the most effective layer of security the organization could have implemented to mitigate the attacker’s ability to gain further information. Logical network segmentation is the process of dividing a network into smaller subnetworks or segments based on criteria such as function, location, or security level. Logical network segmentation can be implemented at the switches, which are devices that operate at the data link layer of the OSI model and forward data packets based on the MAC addresses. Logical network segmentation can provide several benefits, such as:

• Isolating network traffic and reducing congestion and collisions
• Enhancing performance and efficiency of the network
• Improving security and confidentiality of the network
• Restricting the scope and impact of attacks
• Enforcing access control and security policies
• Facilitating monitoring and auditing of the network

Logical network segmentation can mitigate the attacker’s ability to gain further information by limiting the visibility and access of the sniffer to the segment where it is installed. A sniffer is a tool that captures and analyzes the data packets that are transmitted over a network. A sniffer can be used for legitimate purposes, such as troubleshooting, testing, or monitoring the network, or for malicious purposes, such as eavesdropping, stealing, or modifying the data. A sniffer can only capture the data packets that are within its broadcast domain, which is the set of devices that can communicate with each other without a router. By implementing logical network segmentation at the switches, the organization can create multiple broadcast domains and isolate the sensitive or critical data from the compromised segment. This way, the attacker can only see the data packets that belong to the same segment as the sniffer, and not the data packets that belong to other segments. This can prevent the attacker from gaining further information or accessing other resources on the network.

The other options are not the most effective layers of security the organization could have implemented to mitigate the attacker’s ability to gain further information, but rather layers that have other limitations or drawbacks. Implementing packet filtering on the network firewalls is not the most effective layer of security, because packet filtering only examines the network layer header of the data packets, such as the source and destination IP addresses, and does not inspect the payload or the content of the data. Packet filtering can also be bypassed by using techniques such as IP spoofing or fragmentation. Installing Host Based Intrusion Detection Systems (HIDS) is not the most effective layer of security, because HIDS only monitors and detects the activities and events on a single host, and does not prevent or respond to the attacks. HIDS can also be disabled or evaded by the attacker if the host is compromised. Requiring strong authentication for administrators is not the most effective layer of security, because authentication only verifies the identity of the users or processes, and does not protect the data in transit or at rest. Authentication can also be defeated by using techniques such as phishing, keylogging, or credential theft.

Adding a new rule to the application layer firewall is the most suited to quickly implement a control for an input validation and exception handling vulnerability on a critical web-based system. An input validation and exception handling vulnerability is a type of vulnerability that occurs when a web-based system does not properly check, filter, or sanitize the input data that is received from the users or other sources, or does not properly handle the errors or exceptions that are generated by the system. An input validation and exception handling vulnerability can lead to various attacks, such as:

• Injection attacks, such as SQL injection, command injection, or cross-site scripting (XSS), where the attacker inserts malicious code or commands into the input data that are executed by the system or the browser, resulting in data theft, data manipulation, or remote code execution.
• Buffer overflow attacks, where the attacker sends more input data than the system can handle, causing the system to overwrite the adjacent memory locations, resulting in data corruption, system crash, or arbitrary code execution.
• Denial-of-service (DoS) attacks, where the attacker sends malformed or invalid input data that cause the system to generate excessive errors or exceptions, resulting in system overload, resource exhaustion, or system failure.

An application layer firewall is a device or software that operates at the application layer of the OSI model and inspects the application layer payload or the content of the data packets. An application layer firewall can provide various functions, such as:

• Filtering the data packets based on the application layer protocols, such as HTTP, FTP, or SMTP, and the application layer attributes, such as URLs, cookies, or headers.
• Blocking or allowing the data packets based on the predefined rules or policies that specify the criteria for the application layer protocols and attributes.
• Logging and auditing the data packets for the application layer protocols and attributes.
• Modifying or transforming the data packets for the application layer protocols and attributes.

Adding a new rule to the application layer firewall is the most suited to quickly implement a control for an input validation and exception handling vulnerability on a critical web-based system, because it can prevent or reduce the impact of the attacks by filtering or blocking the malicious or invalid input data that exploit the vulnerability. For example, a new rule can be added to the application layer firewall to:

• Reject or drop the data packets that contain SQL statements, shell commands, or script tags in the input data, which can prevent or reduce the injection attacks.
• Reject or drop the data packets that exceed a certain size or length in the input data, which can prevent or reduce the buffer overflow attacks.
• Reject or drop the data packets that contain malformed or invalid syntax or characters in the input data, which can prevent or reduce the DoS attacks.

Adding a new rule to the application layer firewall can be done quickly and easily, without requiring any changes or patches to the web-based system, which can be time-consuming and risky, especially for a critical system. Adding a new rule to the application layer firewall can also be done remotely and centrally, without requiring any physical access or installation on the web-based system, which can be inconvenient and costly, especially for a distributed system.

The other options are not the most suited to quickly implement a control for an input validation and exception handling vulnerability on a critical web-based system, but rather options that have other limitations or drawbacks. Blocking access to the service is not the most suited option, because it can cause disruption and unavailability of the service, which can affect the business operations and customer satisfaction, especially for a critical system. Blocking access to the service can also be a temporary and incomplete solution, as it does not address the root cause of the vulnerability or prevent the attacks from occurring again. Installing an Intrusion Detection System (IDS) is not the most suited option, because IDS only monitors and detects the attacks, and does not prevent or respond to them. IDS can also generate false positives or false negatives, which can affect the accuracy and reliability of the detection. IDS can also be overwhelmed or evaded by the attacks, which can affect the effectiveness and efficiency of the detection. Patching the application source code is not the most suited option, because it can take a long time and require a lot of resources and testing to identify, fix, and deploy the patch, especially for a complex and critical system. Patching the application source code can also introduce new errors or vulnerabilities, which can affect the functionality and security of the system. Patching the application source code can also be difficult or impossible, if the system is proprietary or legacy, which can affect the feasibility and compatibility of the patch.

Data at rest on a Storage Area Network (SAN) is located at the physical layer of the Open System Interconnection (OSI) model. The OSI model is a conceptual framework that describes how data is transmitted and processed across different layers of a network. The OSI model consists of seven layers: application, presentation, session, transport, network, data link, and physical. The physical layer is the lowest layer of the OSI model, and it is responsible for the transmission and reception of raw bits over a physical medium, such as cables, wires, or optical fibers. The physical layer defines the physical characteristics of the medium, such as voltage, frequency, modulation, connectors, etc. The physical layer also deals with the physical topology of the network, such as bus, ring, star, mesh, etc.

A Storage Area Network (SAN) is a dedicated network that provides access to consolidated and block-level data storage. A SAN consists of storage devices, such as disks, tapes, or arrays, that are connected to servers or clients via a network infrastructure, such as switches, routers, or hubs. A SAN allows multiple servers or clients to share the same storage devices, and it provides high performance, availability, scalability, and security for data storage. Data at rest on a SAN is located at the physical layer of the OSI model, because it is stored as raw bits on the physical medium of the storage devices, and it is accessed by the servers or clients through the physical medium of the network infrastructure.

The transport layer of the Transmission Control Protocol/Internet Protocol (TCP/IP) stack is responsible for negotiating and establishing a connection with another node. The TCP/IP stack is a simplified version of the OSI model, and it consists of four layers: application, transport, internet, and link. The transport layer is the third layer of the TCP/IP stack, and it is responsible for providing reliable and efficient end-to-end data transfer between two nodes on a network. The transport layer uses protocols, such as Transmission Control Protocol (TCP) or User Datagram Protocol (UDP), to segment, sequence, acknowledge, and reassemble the data packets, and to handle error detection and correction, flow control, and congestion control. The transport layer also provides connection-oriented or connectionless services, depending on the protocol used.

TCP is a connection-oriented protocol, which means that it establishes a logical connection between two nodes before exchanging data, and it maintains the connection until the data transfer is complete. TCP uses a three-way handshake to negotiate and establish a connection with another node. The three-way handshake works as follows:

• The client sends a SYN (synchronize) packet to the server, indicating its initial sequence number and requesting a connection.
• The server responds with a SYN-ACK (synchronize-acknowledge) packet, indicating its initial sequence number and acknowledging the client’s request.
• The client responds with an ACK (acknowledge) packet, acknowledging the server’s response and completing the connection.

UDP is a connectionless protocol, which means that it does not establish or maintain a connection between two nodes, but rather sends data packets independently and without any guarantee of delivery, order, or integrity. UDP does not use a handshake or any other mechanism to negotiate and establish a connection with another node, but rather relies on the application layer to handle any connection-related issues.

WEP uses a small range Initialization Vector (IV) is the factor that contributes to the weakness of Wired Equivalent Privacy (WEP) protocol. WEP is a security protocol that provides encryption and authentication for wireless networks, such as Wi-Fi. WEP uses the RC4 stream cipher to encrypt the data packets, and the CRC-32 checksum to verify the data integrity. WEP also uses a shared secret key, which is concatenated with a 24-bit Initialization Vector (IV), to generate the keystream for the RC4 encryption. WEP has several weaknesses and vulnerabilities, such as:

• WEP uses a small range Initialization Vector (IV), which results in 16,777,216 (2^24) possible values. This might seem large, but it is not enough for a high-volume wireless network, where the same IV can be reused frequently, creating keystream reuse and collisions. An attacker can capture and analyze the encrypted data packets that use the same IV, and recover the keystream and the secret key, using techniques such as the Fluhrer, Mantin, and Shamir (FMS) attack, or the KoreK attack.
• WEP uses a weak integrity check, which is the CRC-32 checksum. The CRC-32 checksum is a linear function that can be easily computed and manipulated by anyone who knows the keystream. An attacker can modify the encrypted data packets and the checksum, without being detected, using techniques such as the bit-flipping attack, or the chop-chop attack.
• WEP uses a static and shared secret key, which is manually configured and distributed among all the wireless devices that use the same network. The secret key is not changed or refreshed automatically, unless the administrator does it manually. This means that the secret key can be exposed or compromised over time, and that all the wireless devices can be affected by a single key breach. An attacker can also exploit the weak authentication mechanism of WEP, which is based on the secret key, and gain unauthorized access to the network, using techniques such as the authentication spoofing attack, or the shared key authentication attack.

WEP has been deprecated and replaced by more secure protocols, such as Wi-Fi Protected Access (WPA) or Wi-Fi Protected Access II (WPA2), which use stronger encryption and authentication methods, such as the Temporal Key Integrity Protocol (TKIP), the Advanced Encryption Standard (AES), or the Extensible Authentication Protocol (EAP).

The other options are not factors that contribute to the weakness of WEP, but rather factors that are irrelevant or incorrect. WEP does not use Message Digest 5 (MD5), which is a hash function that produces a 128-bit output from a variable-length input. WEP does not use Diffie-Hellman, which is a method for generating a shared secret key between two parties. WEP does use an Initialization Vector (IV), which is a 24-bit value that is concatenated with the secret key.