Which of the following is the below pseudo-code an example of?
IF VARIABLE (CONTAINS NUMBERS = TRUE) THEN EXIT
A. Buffer overflow prevention
B. Input validation
C. CSRF prevention
D. Cross-site scripting prevention
Correct Answer: B
Section: Application, Data and Host Security
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.
A: Buffer overflow is an exploit at programming error, bugs and flaws. It occurs when an application is fed more input data than it is programmed to handle. This may cause the
application to terminate or to write data beyond the end of the allocated space in memory. The termination of the application may cause the system to send the data with temporary
access to privileged levels in the system, while overwriting can cause important data to be lost. Proper error and exception handling and input validation will help prevent Buffer
C: XSRF or cross-site request forgery applies to web applications and is an attack that exploits the web application’s trust of a user who known or is supposed to have been
authenticated. This is often accomplished without the user’s knowledge.
XSRF can be prevented by adding a randomization string (called a nonce) to each URL request and session establishment and checking the client HTTP request header referrer for
D: Cross-site scripting (XSS) is a form of malicious code-injection attack on a web server in which an attacker injects code into the content sent to website visitors. XSS can be
mitigated by implementing patch management on the web server, using firewalls, and auditing for suspicious activity.
Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 257, 338
Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 192, 197, 319, 320