Without validating user input, an application becomes vulnerable to all of the following EXCEPT:
A. Buffer overflow.
B. Command injection.
C. Spear phishing.
D. SQL injection.
Correct Answer: C
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
B: Command injection is often used to gain access to restricted directories on a web server. Proper input validation will help prevent command injection attacks.
D: SQL injection attacks use unexpected input to a web application to gain access to the database used by web application. You can protect a web application against SQL injection by
implementing input validation and by limiting database account privileges for the account used by the web server and the web application.
Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 257, 337, 338
Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 195-196, 197, 319