CAS-004 Dumps with Practice Exam Questions Answers

Public keys on both endpoints are required for implementing PKI-based mutual authentication. PKI stands for Public Key Infrastructure, which is a system that manages the creation, distribution, and verification of certificates. Certificates are digital documents that contain public keys and identity information of their owners. Certificates are issued by trusted authorities called Certificate Authorities (CAs), and can be used to prove the identity and authenticity of the certificate holders. Mutual authentication is a process in which two parties authenticate each other at the same time using certificates. Mutual authentication can provide stronger security and privacy than one-way authentication, where only one party is authenticated. In PKI-based mutual authentication, each party has a certificate that contains its public key and identity information, and a private key that corresponds to its public key. The private key is kept secret and never shared with anyone, while the public key is shared and used to verify the identity and signature of the certificate holder. The basic steps of PKI-based mutual authentication are as follows:

• Party A sends its certificate to Party B.
• Party B verifies Party A’s certificate by checking its validity, signature, and trust chain. If the certificate is valid and trusted, Party B extracts Party A’s public key from the certificate.
• Party B generates a random challenge (such as a nonce or a timestamp) and encrypts it with Party A’s public key. Party B sends the encrypted challenge to Party A.
• Party A decrypts the challenge with its private key and sends it back to Party B.
• Party B compares the received challenge with the original one. If they match, Party B confirms that Party A is the legitimate owner of the certificate and has possession of the private key.
• The same steps are repeated in reverse, with Party A verifying Party B’s certificate and sending a challenge encrypted with Party B’s public key.

A. Perfect forward secrecy on both endpoints is not required for implementing PKI-based mutual authentication. Perfect forward secrecy (PFS) is a property of encryption protocols that ensures that the compromise of a long-term secret key (such as a private key) does not affect the security of past or future session keys (such as symmetric keys). PFS can enhance the security and privacy of encrypted communications, but it does not provide authentication by itself.

B. Shared secret for both endpoints is not required for implementing PKI-based mutual authentication. Shared secret is a method of authentication that relies on a pre-shared piece of information (such as a password or a passphrase) that is known only to both parties. Shared secret can provide simple and fast authentication, but it does not provide non-repudiation or identity verification.

D. A common public key on each endpoint is not required for implementing PKI-based mutual authentication. A common public key on each endpoint would imply that both parties share the same certificate and private key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

E. A common private key on each endpoint is not required for implementing PKI-based mutual authentication. A common private key on each endpoint would imply that both parties share the same certificate and public key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

Field masking is a technique that hides or obscures part of the information in a data field, such as a password, credit card number, or social security number. Field masking can be used to protect sensitive or confidential data from unauthorized access or disclosure, while still allowing authorized users to view or verify the data.

Field masking should be implemented to authenticate employees who call in remotely by allowing the help desk staff to view partial information about employees, because field masking would:

• Enable the help desk staff to verify the identity of the employees by asking them to provide some characters or digits from their data fields, such as their employee ID or email address.
• Prevent the help desk staff from viewing the full information about employees, which may be considered sensitive and subject to privacy regulations or policies.
• Reduce the risk of data leakage, theft, or misuse by limiting the exposure of sensitive data to only those who need it.

WAP A: No issue found. The WAP A is configured correctly and meets the requirements.

PC A = Enable host-based firewall to block all traffic

This option will turn off the host-based firewall and allow all traffic to pass through. This will comply with the requirement and also improve the connectivity of PC A to other devices on the network. However, this option will also reduce the security of PC A and make it more vulnerable to attacks. Therefore, it is recommended to use other security measures, such as antivirus, encryption, and password complexity, to protect PC A from potential threats.

Laptop A: Patch management

This option will install the updates that are available for Laptop A and ensure that it has the most recent security patches and bug fixes. This will comply with the requirement and also improve the performance and stability of Laptop A. However, this option may also require a reboot of Laptop A and some downtime during the update process. Therefore, it is recommended to backup any important data and close any open applications before applying the updates.

Switch A: No issue found. The Switch A is configured correctly and meets the requirements.

Switch B: No issue found. The Switch B is configured correctly and meets the requirements.

Laptop B: Disable unneeded services

This option will stop and disable the telnet service that is using port 23 on Laptop B. Telnet is a cleartext service that transmits data in plain text over the network, which exposes it to eavesdropping, interception, and modification by attackers. By disabling the telnet service, you will comply with the requirement and also improve the security of Laptop B. However, this option may also affect the functionality of Laptop B if it needs to use telnet for remote administration or other purposes. Therefore, it is recommended to use a secure alternative to telnet, such as SSH or HTTPS, that encrypts the data in transit.

PC B: Enable disk encryption

This option will encrypt the HDD of PC B using a tool such as BitLocker or VeraCrypt. Disk encryption is a technique that protects data at rest by converting it into an unreadable format that can only be decrypted with a valid key or password. By enabling disk encryption, you will comply with the requirement and also improve the confidentiality and integrity of PC B’s data. However, this option may also affect the performance and usability of PC B, as it requires additional processing time and user authentication to access the encrypted data. Therefore, it is recommended to backup any important data and choose a strong key or password before encrypting the disk.

PC C: Disable unneeded services

This option will stop and disable the SSH daemon that is using port 22 on PC C. SSH is a secure service that allows remote access and command execution over an encrypted channel. However, port 22 is the default and well-known port for SSH, which makes it a common target for brute-force attacks and port scanning. By disabling the SSH daemon on port 22, you will comply with the requirement and also improve the security of PC C. However, this option may also affect the functionality of PC C if it needs to use SSH for remote administration or other purposes. Therefore, it is recommended to enable the SSH daemon on a different port, such as 4022, by editing the configuration file using the following command:

sudo nano /etc/ssh/sshd_config

Server A. Need to select the following:

A black and white screen with white text Description automatically generated

Implementing an ongoing, third-party software and library review and regression testing is the best way to maximize risk reduction from vulnerabilities introduced by OpenSSL. Third-party software and libraries are often used by developers to save time and resources, but they may also introduce security risks if they are not properly maintained and updated. By reviewing and testing the third-party software and library regularly, the company can ensure that they are using the latest and most secure version of OpenSSL, and that their proprietary software is compatible and functional with it.

References: [CompTIA CASP+ Study Guide, Second Edition, page 362]

The security analyst acknowledges this alert because it is a false positive. A false positive is an event classification that indicates a benign or normal activity is mistakenly flagged as malicious or suspicious by the SIEM system. A false positive can occur due to misconfigured rules, outdated signatures, or faulty algorithms. A false positive can waste the security analyst’s time and resources, so it is important to acknowledge and dismiss it after verifying that it is not a real threat. Verified References:

• https://www.ibm.com/topics/siem
• https://www.microsoft.com/en-us/security/business/security-101/what-is-siem
• https://www.splunk.com/en_us/data-insider/what-is-siem.html