CAS-004 Exam Dumps - CompTIA SecurityX Certification Exam

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 nevershared 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.

Deploying a web application firewall (WAF) signature is a way to detect and block attempts to exploit the Heartbleed vulnerability on the web server. A WAF signature is a pattern that matches a known attack vector, such as a malicious heartbeat request. By deploying a WAF signature, the company can protect its web application from Heartbleed attacks until the underlying vulnerability is fixed.

Updating the OpenSSL library is the ultimate way to fix and mitigate the Heartbleed vulnerability. The OpenSSL project released version 1.0.1g on April 7, 2014, which patched the bug by adding a bounds check to the heartbeat function. By updating the OpenSSL library on the web server, the company can eliminate the vulnerability and prevent any future exploitation.

B. Fixing the PHP code is not a way to resolve or mitigate the Heartbleed vulnerability, because the vulnerability is not in the PHP code, but in the OpenSSL library that handles the SSL/TLS encryption for the web server.

C. Changing the web server from HTTPS to HTTP is not a way to resolve or mitigate the Heartbleed vulnerability, because it would expose all the web traffic to eavesdropping and tampering by attackers. HTTPS provides confidentiality, integrity, and authentication for web communications, and should not be disabled for security reasons.

D. Using SSLv3 is not a way to resolve or mitigate the Heartbleed vulnerability, because SSLv3 is an outdated and insecure protocol that has been deprecated and replaced by TLS. SSLv3 does not support modern cipher suites, encryption algorithms, or security features, and is vulnerable to various attacks, such as POODLE.

E. Changing the code from PHP to ColdFusion is not a way to resolve or mitigate the Heartbleed vulnerability, because the vulnerability is not related to the programming language of the web application, but to the OpenSSL library that handles the SSL/TLS encryption for the web server.

https://owasp.org/www-community/vulnerabilities/Heartbleed_Bug

https://heartbleed.com/

Key escrow is the system responsible for storing private encryption/decryption files with a third party to ensure these files are stored safely. Key escrow is an arrangement in which the keys needed to decrypt encrypted data are held in escrow by a trusted third party that can release them under certain conditions. Key escrow can be useful for backup or recovery purposes, or for complying with legal or regulatory requirements that may demand access to encrypted data.

B. TPM is not the system responsible for storing private encryption/decryption files with a third party to ensure these files are stored safely. TPM stands for Trusted Platform Module, which is a hardware device that provides secure storage and generation of cryptographic keys on a computer. TPM does not involve any third party or escrow service.

C. Trust models are not the system responsible for storing private encryption/decryption files with a third party to ensure these files are stored safely. Trust models are frameworks that define how entities can establish and maintain trust relationships in a network or system. Trust models do not necessarily involve any third party or escrow service.

D. Code signing is not the system responsible for storing private encryption/decryption files with a third party to ensure these files are stored safely. Code signing is a process of using digital signatures to verify the authenticity and integrity of software code. Code signing does not involve any third party or escrow service.

The browser is the application that the security analyst should patch first, given that all the applications have equally high CVSS scores. CVSS stands for Common Vulnerability Scoring System, which is a method for measuring the severity of vulnerabilities based on various factors,such as access conditions, impact, and exploitability. CVSS scores range from 0 to 10, with higher scores indicating higher severity. However, CVSS scores alone are not sufficient to determine the patching priority, asthey do not account for other factors, such as the likelihood of exploitation, the exposure of the system, or the criticality of the data. Therefore, the security analyst should also consider the context and the risk of each application when deciding which one to patch first. In this case, the browser is likely to be the most exposed and frequently used application by the network administrator, and also the most likely entry point for an attacker to compromise the system or access the SSO web portal. Therefore, patching the browser first can reduce the risk of a successful attack and protect the system and the data from further damage. Verified References:

https://nvd.nist.gov/vuln-metrics/cvss

https://www.darkreading.com/risk/vulnerability-severity-scores-make-for-poor-patching-priority-researchers-find

The root cause of this issue is that the iOS keychain imported only the client public and private keys, but not the CA certificate. A PKCS#12 file (.p12 or .pfx) is a file format that contains a certificate and its private key, optionally protected by a password. A PKCS#12 file can also contain intermediate certificates or root certificates that are needed to verify the certificate chain. However, when importing a PKCS#12 file into the iOS keychain, only the certificate and its private key are imported, not the CA certificate. This means that the iOS device cannot verify the authenticity of the certificate, and displays the error message “mbedTLS: ca certificate undefined”. To fix this issue, the CA certificate needs to be imported separately into the iOS keychain, either manually or using a configuration profile. Verified References:

https://developer.apple.com/documentation/devicemanagement/certificatepkcs12

https://support.apple.com/guide/deployment/distribute-certificates-depcdc9a6a3f/web

https://openvpn.net/faq/how-do-i-use-a-client-certificate-and-private-key-from-the-ios-keychain/

Homomorphic encryption is a type of encryption method that allows computations to be performed on encrypted data without first decrypting it with a secret key. The results of the computations also remain encrypted and can only be decrypted by the owner of the private key. Homomorphic encryption can be used for privacy-preserving outsourced storage and computation. This means that data can be encrypted and sent to a cloud service provider (CSP) for processing, without revealing any information to the CSP or anyone else who might intercept the data. Homomorphic encryption can enable new services and applications that require processing confidential data on a large number of resources, such as machine learning, data analytics, health care, finance, and voting.

A. Processing data on a server after decrypting in order to prevent unauthorized access in transit is not a common use case for homomorphic encryption, because it does not take advantage of the main feature of homomorphic encryption, which is computing over encrypted data. This use casecan be achieved by using any standard encryption method that provides confidentiality for data in transit.

B. Maintaining the confidentiality of data both at rest and in transit to and from a CSP for processing is not a common use case for homomorphic encryption, because it does not take advantage of the main feature of homomorphic encryption, which is computing over encrypted data. This use case can be achieved by using any standard encryption method that provides confidentiality for data at rest and in transit.

D. Storing proprietary data across multiple nodes in a private cloud to prevent access by unauthenticated users is not a common use case for homomorphic encryption, because it does not involve any computation over encrypted data. This use case can be achieved by using any standard encryption method that provides confidentiality for data at rest.

https://www.splunk.com/en_us/blog/learn/homomorphic-encryption.html

https://research.aimultiple.com/homomorphic-encryption/

Resource exhaustion is a condition that occurs when a system or service runs out of resources, such as memory, CPU, disk space, or bandwidth, and becomes unable to function properly or respond torequests. Resource exhaustion can be caused by high demand, poor design, misconfiguration, or malicious attacks, such as denial-of-service (DoS).

Resource exhaustion would be the most significant business risk to a company that signs a contract with a cloud service provider (CSP) that is able to provide the same uptime as other CSPs at a markedly reduced cost, because this could:

Indicate that the CSP is oversubscribing or underprovisioning its resources, which could result in performance degradation, service disruption, or data loss for the company.

Affect the company’s availability, reliability, and scalability requirements, which could impact its operations, reputation, and customer satisfaction.

Expose the company to potential security breaches or compliance violations, if the CSP does not implement adequate security controls or measures to prevent or mitigate resource exhaustion.

Reviewing video from IP cameras within the facility would be the most likely process to expose an attacker who has compromised an air-gapped system. Since air-gapped systems are isolated from external networks, an attacker would need physical access to the system or use some covert channel to communicate with it. Video surveillance could reveal any unauthorized or suspicious activity within the facility that could be related to the attack. Verified References:

https://www.welivesecurity.com/wp-content/uploads/2021/12/eset_jumping_the_air_gap_wp.pdf

https://en.wikipedia.org/wiki/Air-Gap_Malware

https://www.techtarget.com/searchsecurity/essentialguide/How-air-gap-attacks-challenge-the-notion-of-secure-networks