CompTIA Security+ Question K-21

Peter, the security administrator, has been notified by the IDS that the company website is under attack. Analysis of the web logs show the following string, indicating a user is trying to post a comment on the public bulletin board.
INSERT INTO message `
This is an example of which of the following?

A. XSS attack
B. XML injection attack
C. Buffer overflow attack
D. SQL injection attack

Answer: A

Explanation:
The tags indicate that script is being inserted. Cross-site scripting (XSS) is a type of computer security vulnerability typically found in Web applications. XSS enables attackers to inject client-side script into Web pages viewed by other users. Cross-site scripting uses known vulnerabilities in web-based applications, their servers, or plug-in systems on which they rely. Exploiting one of these, attackers fold malicious content into the content being delivered from the compromised site. When the resulting combined content arrives at the client-side web browser, it has all been delivered from the trusted source, and thus operates under the permissions granted to that system. By finding ways of injecting malicious scripts into web pages, an attacker can gain elevated access-privileges to sensitive page content, session cookies, and a variety of other information maintained by the browser on behalf of the user.

CompTIA Security+ Question D-1

Which of the following was launched against a company based on the following IDS log?
122.41.15.252 – – [21/May/2012:00:17:20 +1200] “GET
/index.php?username=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA A
AAA HTTP/1.1″ 200 2731 “http://www.company.com/cgibin/
forum/commentary.pl/noframes/read/209″ “Mozilla/4.0 (compatible;
MSIE 6.0; Windows NT 5.1; Hotbar 4.4.7.0)”

A. SQL injection
B. Buffer overflow attack
C. XSS attack
D. Online password crack

Answer: B

Explanation:
The username should be just a username; instead we can see it’s a long line of text with an HTTP command in it. This is an example of a buffer overflow attack. A buffer overflow occurs when a program or process tries to store more data in a buffer (temporary data storage area) than it was intended to hold. Since buffers are created to contain a finite amount of data, the extra information – which has to go somewhere – can overflow into adjacent buffers, corrupting or overwriting the valid data held in them. Although it may occur accidentally through programming error, buffer overflow is an increasingly common type of security attack on data integrity. In buffer overflow attacks, the extra data may contain codes designed to trigger specific actions, in effect sending new instructions to the attacked computer that could, for example, damage the user’s files, change data, or disclose confidential information. Buffer overflow attacks are said to have arisen because the C programming language supplied the framework, and poor programming practices supplied the vulnerability.