CompTIA Security+ Question C-100

Ann is an employee in the accounting department and would like to work on files from her home computer. She recently heard about a new personal cloud storage service with an easy web interface. Before uploading her work related files into the cloud for access, which of the following is the MOST important security concern Ann should be aware of?

A. Size of the files
B. Availability of the files
C. Accessibility of the files from her mobile device
D. Sensitivity of the files

Answer: D

Explanation:
Cloud computing has privacy concerns, regulation compliance difficulties, use of open-/closed­source solutions, and adoption of open standards. It is also unsure whether cloud-based data is actually secured (or even securable).

CompTIA Security+ Question C-99

Company XYZ has encountered an increased amount of buffer overflow attacks. The programmer has been tasked to identify the issue and report any findings. Which of the following is the FIRST step of action recommended in this scenario?

A. Baseline Reporting
B. Capability Maturity Model
C. Code Review
D. Quality Assurance and Testing

Answer: C

Explanation:
A buffer overflow attack attacks a vulnerability caused by poor coding in an application. Reviewing the code of the application will enable you to identify code that is vulnerable to buffer overflow.

A buffer overflow occurs when a program or process tries to store more data in a buffer (temporary data storage area) than it was intended to hold. Since buffers are created to contain a finite amount of data, the extra information – which has to go somewhere – can overflow into adjacent buffers, corrupting or overwriting the valid data held in them. Although it may occur accidentally through programming error, buffer overflow is an increasingly common type of security attack on data integrity. In buffer overflow attacks, the extra data may contain codes designed to trigger specific actions, in effect sending new instructions to the attacked computer that could, for example, damage the user’s files, change data, or disclose confidential information. Buffer overflow attacks are said to have arisen because the C programming language supplied the framework, and poor programming practices supplied the vulnerability.

CompTIA Security+ Question C-98

Ann, the system administrator, is installing an extremely critical system that can support ZERO downtime. Which of the following BEST describes the type of system Ann is installing?

A. High availability
B. Clustered
C. RAID
D. Load balanced

Answer: A

Explanation:
High Availability is he term used to refer to a system that has been secured and set up/configured in such a way so as to be online, active and able to respond and thus have zero downtime as a result.

CompTIA Security+ Question C-97

Peter, the security engineer, would like to prevent wireless attacks on his network. Peter has implemented a security control to limit the connecting MAC addresses to a single port. Which of the following wireless attacks would this address?

A. Interference
B. Man-in-the-middle
C. ARP poisoning
D. Rogue access point

Answer: D

Explanation:
MAC filtering is typically used in wireless networks. In computer networking, MAC Filtering (or GUI filtering, or layer 2 address filtering) refers to a security access control method whereby the 48-bit address assigned to each network card is used to determine access to the network. MAC addresses are uniquely assigned to each card, so using MAC filtering on a network permits and denies network access to specific devices through the use of blacklists and whitelists.

In this question, a rogue access point would need to be able to connect to the network to provide access to network resources. If the MAC address of the rogue access point isn’t allowed to connect to the network port, then the rogue access point will not be able to connect to the network.

CompTIA Security+ Question C-96

Which of the following is used to verify data integrity?

A. SHA
B. 3DES
C. AES
D. RSA

Answer: A

Explanation:
SHA stands for “secure hash algorithm”. SHA-1 is the most widely used of the existing SHA hash functions, and is employed in several widely used applications and protocols including TLS and SSL, PGP, SSH, S/MIME, and IPsec. It is used to ensure data integrity.

Note: A hash value (or simply hash), also called a message digest, is a number generated from a string of text. The hash is substantially smaller than the text itself, and is generated by a formula in such a way that it is extremely unlikely that some other text will produce the same hash value.

Hashes play a role in security systems where they’re used to ensure that transmitted messages have not been tampered with. The sender generates a hash of the message, encrypts it, and sends it with the message itself. The recipient then decrypts both the message and the hash, produces another hash from the received message, and compares the two hashes. If they’re the same, there is a very high probability that the message was transmitted intact. This is how hashing is used to ensure data integrity.

CompTIA Security+ Question C-95

Emily, an employee, tethers her smartphone to her work PC to bypass the corporate web security gateway while connected to the LAN. While Emily is out at lunch her PC is compromised via the tethered connection and corporate data is stolen. Which of the following would BEST prevent this from occurring again?

A. Disable the wireless access and implement strict router ACLs.
B. Reduce restrictions on the corporate web security gateway.
C. Security policy and threat awareness training.
D. Perform user rights and permissions reviews.

Answer: C

Explanation:
BYOD (In this case Emily’s smart phone) involves the possibility of a personal device that is infected with malware introducing that malware to the network and security awareness training will address the issue of the company’s security policy with regard to BYOD.

CompTIA Security+ Question C-94

The public key is used to perform which of the following? (Select THREE).

A. Validate the CRL
B. Validate the identity of an email sender
C. Encrypt messages
D. Perform key recovery
E. Decrypt messages
F. Perform key escrow

Answer: B,C,E

Explanation:
B: The sender uses the private key to create a digital signature. The message is, in effect, signed with the private key. The sender then sends the message to the receiver. The receiver uses the public key attached to the message to validate the digital signature. If the values match, the receiver knows the message is authentic.

C: The sender uses the public key to encrypt a message, and the receiver uses the private key to decrypt the message.

E: You encrypt data with the private key and decrypt with the public key, though the opposite is much more frequent. Public-key cryptography, also known as asymmetric cryptography, is a class of cryptographic protocols based on algorithms that require two separate keys, one of which is secret (or private) and one of which is public. Although different, the two parts of this key pair are mathematically linked.

CompTIA Security+ Question C-93

Which of the following BEST explains the use of an HSM within the company servers?

A. Thumb drives present a significant threat which is mitigated by HSM.
B. Software encryption can perform multiple functions required by HSM.
C. Data loss by removable media can be prevented with DLP.
D. Hardware encryption is faster than software encryption.

Answer: D

Explanation:
Hardware Security Module (HSM) is a cryptoprocessor that can be used to enhance security. It provides a fast solution for the for large asymmetrical encryption calculations and is much faster than software-based cryptographic solutions.

CompTIA Security+ Question C-92

A systems engineer has been presented with storage performance and redundancy requirements for a new system to be built for the company. The storage solution must be designed to support the highest performance and must also be able to support more than one drive failure. Which of the following should the engineer choose to meet these requirements?

A. A mirrored striped array with parity
B. A mirrored mirror array
C. A striped array
D. A striped array with parity

Answer: B

Explanation:
Mirroring means the data written to one drive is exactly duplicated to a second drive in real time. Disk mirroring is also known as RAID 1 and the data is intact in a RAID 1 array if either one of the two drives fails. After the failed drive is replaced with a new drive, you remirror the data from the good drive to the new drive to re-create the array.

CompTIA Security+ Question C-91

Which of the following defines a business goal for system restoration and acceptable data loss?

A. MTTR
B. MTBF
C. RPO
D. Warm site

Answer: C

Explanation:
The recovery point objective (RPO) defines the point at which the system needs to be restored. This could be where the system was two days before it crashed (whip out the old backup tapes) or five minutes before it crashed (requiring complete redundancy). This is an essential business goal insofar as system restoration and acceptable data loss is concerned.