Ch 21 Flashcards
- What is the most commonly used technique to protect against virus attacks?
A. Signature detection
B. Heuristic detection
C. Data integrity assurance
D. Automated reconstruction
Answer: A
Signature detection mechanisms use known descriptions of viruses to identify malicious code resident on a system.
- You are the security administrator for an e-commerce company and are placing a new web server into production. What network zone should you use?
A. Internet
B. DMZ
C. Intranet
D. Sandbox
Answer: B
The DMZ (demilitarized zone) is designed to house systems like web servers that must be accessible from both the internal and external networks.
- Which one of the following types of attacks relies on the difference between the timing of two events?
A. Smurf
B. TOCTTOU
C. Land
D. Fraggle
Answer: B
The time-of-check-to-time-of-use (TOCTTOU) attack relies on the timing of the execution of two events.
- Which of the following techniques requires that administrators identify appropriate applications for an environment?
A. Sandboxing
B. Control signing
C. Integrity monitoring
D. Whitelisting
Answer: D
Application whitelisting requires that administrators specify approved applications, and then the operating system uses this list to allow only known good applications to run.
- What advanced virus technique modifies the malicious code of a virus on each system it infects?
A. Polymorphism
B. Stealth
C. Encryption
D. Multipartitism
Answer: A
In an attempt to avoid detection by signature-based antivirus software packages, polymorphic viruses modify their own code each time they infect a system.
- Which one of the following tools provides a solution to the problem of users forgetting complex passwords?
A. LastPass
B. Crack
C. Shadow password files
D. Tripwire
Answer: A
LastPass is a tool that allows users to create unique, strong passwords for each service they use without the burden of memorizing them all.
- What type of application vulnerability most directly allows an attacker to modify the contents of a system’s memory?
A. Rootkit
B. Back door
C. TOC/TOU
D. Buffer overflow
Answer: D
Buffer overflow attacks allow an attacker to modify the contents of a system’s memory by writing beyond the space allocated for a variable.
- Which one of the following passwords is least likely to be compromised during a dictionary attack?
A. mike
B. elppa
C. dayorange
D. fsas3a1G
Answer: D
Except option D, the choices are forms of common words that might be found during a dictionary attack. mike is a name and would be easily detected. elppa is simply apple spelled backward, and dayorange combines two dictionary words. Crack and other utilities can easily see through these “sneaky” techniques. Option D is simply a random string of characters that a dictionary attack would not uncover.
- What file is instrumental in preventing dictionary attacks against Unix systems?
A. /etc/passwd
B. /etc/shadow
C. /etc/security
D. /etc/pwlog
Answer: B
Shadow password files move encrypted password information from the publicly readable /etc/passwd file to the protected /etc/shadow file.
- What character should always be treated carefully when encountered as user input on a web form?
A. !
B. &
C. *
D. ‘
Answer: D
The single quote character (‘) is used in SQL queries and must be handled carefully on web forms to protect against SQL injection attacks.
- What database technology, if implemented for web forms, can limit the potential for SQL injection attacks?
A. Triggers
B. Stored procedures
C. Column encryption
D. Concurrency control
Answer: B
Developers of web applications should leverage database stored procedures to limit the application’s ability to execute arbitrary code. With stored procedures, the SQL statement resides on the database server and may only be modified by database administrators.
- What type of reconnaissance attack provides attackers with useful information about the services running on a system?
A. Session hijacking
B. Port scan
C. Dumpster diving
D. IP sweep
Answer: B
Port scans reveal the ports associated with services running on a machine and available to the public.
- What condition is necessary on a web page for it to be used in a cross-site scripting attack?
A. Reflected input
B. Database-driven content
C. NET technology
D. CGI scripts
Answer: A
Cross-site scripting attacks are successful only against web applications that include reflected input.
- What type of virus utilizes more than one propagation technique to maximize the number of penetrated systems?
A. Stealth virus
B. Companion virus
C. Polymorphic virus
D. Multipartite virus
Answer: D
Multipartite viruses use two or more propagation techniques (for example, file infection and boot sector infection) to maximize their reach.
- What is the most effective defense against cross-site scripting attacks?
A. Limiting account privileges
B. Input validation
C. User authentication
D. Encryption
Answer: B
Input validation prevents cross-site scripting attacks by limiting user input to a predefined range. This prevents the attacker from including the HTML
