CompTIA Security+ Question L-67

The systems administrator notices that many employees are using passwords that can be easily guessed or are susceptible to brute force attacks. Which of the following would BEST mitigate this risk?

A. Enforce password rules requiring complexity.
B. Shorten the maximum life of account passwords.
C. Increase the minimum password length.
D. Enforce account lockout policies.

Answer: A

Password complexity often requires the use of a minimum of three out of four standard character types for a password. The more characters in a password that includes some character complexity, the more resistant it is to brute force attacks.

CompTIA Security+ Question L-60

Which of the following would be used to identify the security posture of a network without actually exploiting any weaknesses?

A. Penetration test
B. Code review
C. Vulnerability scan
D. Brute Force scan

Answer: C

A vulnerability scan is the automated process of proactively identifying security vulnerabilities of computing systems in a network in order to determine if and where a system can be exploited and/or threatened. While public servers are important for communication and data transfer over the Internet, they open the door to potential security breaches by threat agents, such as malicious hackers. Vulnerability scanning employs software that seeks out security flaws based on a database of known flaws, testing systems for the occurrence of these flaws and generating a report of the findings that an individual or an enterprise can use to tighten the network’s security. Vulnerability scanning typically refers to the scanning of systems that are connected to the Internet but can also refer to system audits on internal networks that are not connected to the Internet in order to assess the threat of rogue software or malicious employees in an enterprise.

CompTIA Security+ Question K-97

Which of the following algorithms has well documented collisions? (Select TWO).

B. MD5
D. SHA-256

Answer: B,C

B: MD5 biggest weakness is that it does not have strong collision resistance, and thus it is no longer recommended for use.

C: SHA-1 (also known as SHA) is being retired from most government uses; the U.S. National Institute of Standards and Technology said, “Federal agencies should stop using SHA-1 for…applications that require collision resistance as soon as practical, and must use the SHA-2 family of hash functions for these applications after 2010”, though that was later relaxed. Note: The hashing algorithm must have few or no collisions. This means that hashing two different inputs does not give the same output. Cryptographic hash functions are usually designed to be collision resistant. But many hash functions that were once thought to be collision resistant were later broken. MD5 and SHA-1 in particular both have published techniques more efficient than brute force for finding collisions.

CompTIA Security+ Question K-57

The information security team does a presentation on social media and advises the participants not to provide too much personal information on social media web sites. This advice would BEST protect people from which of the following?

A. Rainbow tables attacks
B. Brute force attacks
C. Birthday attacks
D. Cognitive passwords attacks

Answer: D

Social Networking Dangers are ‘amplified’ in that social media networks are designed to mass distribute personal messages. If an employee reveals too much personal information it would be easy for miscreants to use the messages containing the personal information to work out possible passwords.

CompTIA Security+ Question J-52

Which of the following application security principles involves inputting random data into a program?

A. Brute force attack
B. Sniffing
C. Fuzzing
D. Buffer overflow

Answer: C

Fuzzing is a software testing technique that involves providing invalid, unexpected, or random data to as inputs to a computer program. The program is then monitored for exceptions such as crashes, or failed validation, or memory leaks.

CompTIA Security+ Question I-76

Account lockout is a mitigation strategy used by Jane, the administrator, to combat which of the following attacks? (Select TWO).

A. Spoofing
B. Man-in-the-middle
C. Dictionary
D. Brute force
E. Privilege escalation

Answer: C,D

Account lockout is a useful method for slowing down online password-guessing attacks. A dictionary attack performs password guessing by making use of a pre-existing list of likely passwords. A brute-force attack is intended to try every possible valid combination of characters to create possible passwords in the attempt to discover the specific passwords used by user accounts.

CompTIA Security+ Question I-46

Use of a smart card to authenticate remote servers remains MOST susceptible to which of the following attacks?

A. Malicious code on the local system
B. Shoulder surfing
C. Brute force certificate cracking
D. Distributed dictionary attacks

Answer: A

Once a user authenticates to a remote server, malicious code on the user’s workstation could then infect the server.

CompTIA Security+ Question H-18

Which of the following can be used by a security administrator to successfully recover a user’s forgotten password on a password protected file?

A. Cognitive password
B. Password sniffing
C. Brute force
D. Social engineering

Answer: C

One way to recover a user’s forgotten password on a password protected file is to guess it. A brute force attack is an automated attempt to open the file by using many different passwords.

A brute force attack is a trial-and-error method used to obtain information such as a user password or personal identification number (PIN). In a brute force attack, automated software is used to generate a large number of consecutive guesses as to the value of the desired data. Brute force attacks may be used by criminals to crack encrypted data, or by security analysts to test an organization’s network security. A brute force attack may also be referred to as brute force cracking. For example, a form of brute force attack known as a dictionary attack might try all the words in a dictionary. Other forms of brute force attack might try commonly-used passwords or combinations of letters and numbers. An attack of this nature can be time- and resource-consuming. Hence the name “brute force attack;” success is usually based on computing power and the number of combinations tried rather than an ingenious algorithm.

CompTIA Security+ Question H-10

Which of the following wireless protocols could be vulnerable to a brute-force password attack? (Select TWO).


Answer: A,E

A brute force attack is an attack that attempts to guess a password. WPA2-PSK and WEP both use a “Pre-Shared Key”. The pre-shared key is a password and therefore is susceptible to a brute force attack.

CompTIA Security+ Question G-97

The security administrator notices a user logging into a corporate Unix server remotely as root. Which of the following actions should the administrator take?

A. Create a firewall rule to block SSH
B. Delete the root account
C. Disable remote root logins
D. Ensure the root account has a strong password

Answer: C

Remote users log in to Unix or Linux servers by using SSH. Although SSH is secure, allowing remote access as root is a security risk.

One of the biggest security holes you could open on a Unix or Linux server is to allow directly logging in as root through SSH, because any cracker can attempt to brute force your root password and potentially get access to your system if they can figure out your password. It’s much better to have a separate account that you regularly use and simply sudo to root when necessary. You should disable root ssh access by editing /etc/ssh/sshd_config to contain: PermitRootLogin no