Which of the following is a common type of attack on web servers?

A.
Buffer overflow

B.
Birthday

C.
Spam

D.
Brute force

Explanation:

Buffer overflow occur when an application receives more data that it is programmed to accept.
This situation can cause an application to terminate. The termination may leave the system
sending the data with temporary access to privileged levels in the attacked system.
Reference:
Mike Pastore and Emmett Dulaney , Security+ Study Guide , 2nd Edition, Alameda , Sybex , 2004,
p 135