CompTIA SY0-401 Free Practice Questions

Answer: C 

Explanation: 

controls such as preventing unauthorized access to PC’s and applying screensavers that lock the PC after five minutes of inactivity is a technical control type, the same as Identification and Authentication, Access Control, Audit and Accountability as well as System and Communication Protection. 

Answer: C 

Explanation: 

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. 

Answer: A 

Explanation: 

A virtual local area network (VLAN) is a hardware-imposed network segmentation created by switches. VLANs are used for traffic management. Communications between ports within the same VLAN occur without hindrance, but communications between VLANs require a routing function. 

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. 

Answer: C 

Explanation: 

Change Management is a risk mitigation approach and refers to the structured approach that is followed to secure a company’s assets. In this case ‘performing updates to business critical systems. 

Answer: B 

Explanation: 

Steganography is the process of concealing a file, message, image, or video within another file, message, image, or video. Note: The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages, no matter how unbreakable will arouse interest, and may in themselves be incriminating in countries where encryption is illegal. Thus, whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing the fact that a secret message is being sent, as well as concealing the contents of the message. 

Answer: B 

Explanation: 

Input validation is a defensive technique intended to mitigate against possible user input attacks, such as buffer overflows and fuzzing. Input validation checks every user input submitted to the application before processing that input. The check could be a length, a character type, a language type, or a domain. 

Answer: C 

Explanation: 

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. 

Answer: D 

Explanation: 

Before creating a CSR, the applicant first generates a key pair, keeping the private key secret. The private key is needed to produce, but it is not part of, the CSR. The private key is an RSA key. The private encryption key that will be used to protect sensitive information. Note: A CSR or Certificate Signing request is a block of encrypted text that is generated on the server that the certificate will be used on. It contains information that will be included in your certificate such as your organization name, common name (domain name), locality, and country. It also contains the public key that will be included in your certificate. A private key is usually created at the same time that you create the CSR. 

Answer: D 

Explanation: 

The code in the question is an example of a SQL Injection attack. The code ‘1=1’ will always provide a value of true. This can be included in statement designed to return all rows in a SQL table. 

SQL injection is a code injection technique, used to attack data-driven applications, in which malicious SQL statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker). SQL injection must exploit a security vulnerability in an application's software, for example, when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and unexpectedly executed. SQL injection is mostly known as an attack vector for websites but can be used to attack any type of SQL database. 

Answer: C 

Explanation: 

WEP's major weakness is its use of static encryption keys. When you set up a router with a WEP encryption key, that one key is used by every device on your network to encrypt every packet that's transmitted. But the fact that packets are encrypted doesn't prevent them from being intercepted, and due to some esoteric technical flaws it's entirely possible for an eavesdropper to intercept enough WEP-encrypted packets to eventually deduce what the key is. This problem used to be something you could mitigate by periodically changing the WEP key (which is why routers generally allow you to store up to four keys). But few bother to do this because changing WEP keys is inconvenient and time-consuming because it has to be done not just on the router, but on every device that connects to it. As a result, most people just set up a single key and then continue using it ad infinitum. Even worse, for those that do change the WEP key, new research and developments reinforce how even changing WEP keys frequently is no longer sufficient to protect a WLAN. The process of 'cracking' a WEP key used to require that a malicious hacker intercept millions of packets plus spend a fair amount of time and computing power. Researchers in the computer science department of a German university recently demonstrated the capability to compromise a WEP-protected network very quickly. After spending less than a minute intercepting data (fewer than 100,000 packets in all) they were able to compromise a WEP key in just three seconds. 

Answer: B 

Explanation: 

In cryptography, RC4 is the most widely used software stream cipher and is used in popular Internet protocols such as Transport Layer Security (TLS). While remarkable for its simplicity and speed in software, RC4 has weaknesses that argue against its use in new systems. It is especially vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or related keys are used; some ways of using RC4 can lead to very insecure protocols such as WEP. 

Because RC4 is a stream cipher, it is more malleable than common block ciphers. If not used together with a strong message authentication code (MAC), then encryption is vulnerable to a bit-flipping attack. The cipher is also vulnerable to a stream cipher attack if not implemented correctly. Furthermore, inadvertent double encryption of a message with the same key may accidentally output plaintext rather than ciphertext because the involutory nature of the XOR function would result in the second operation reversing the first. It is noteworthy, however, that RC4, being a stream cipher, was for a period of time the only common cipher that was immune to the 2011 BEAST attack on TLS 1.0. The attack exploits a known weakness in the way cipher block chaining mode is used with all of the other ciphers supported by TLS 1.0, which are all block ciphers. 

Answer: C,D 

Explanation: 

Answer: A 

Explanation: 

A vulnerability scan is the process of scanning the network and/or I.T. infrastructure for threats and vulnerabilities. The threats and vulnerabilities are then evaluated in a risk assessment and the necessary actions taken to resolve and vulnerabilities. A vulnerability scan scans for known weaknesses such as missing patches or security updates. 

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. 

Answer: C 

Explanation: