A server administrator notes that a legacy application often stops running due to a memory error. When
reviewing the debugging logs, they notice code being run calling an internal process to exploit the
machine. Which of the following attacks does this describe?
A.
Zero-day
B.
Buffer overflow
C.
Cross site scripting
D.
Malicious add-on
Explanation:
This question describes 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, ordisclose 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.
Incorrect Answers:
A: A zero day vulnerability refers to a hole in software that is unknown to the vendor. This security hole is
then exploited by hackers before the vendor becomes aware and hurries to fix it—this exploit is called a
zero day attack. Uses of zero day attacks can include infiltrating malware, spyware or allowing unwanted
access to user information. The term “zero day” refers to the unknown nature of the hole to those
outside of the hackers, specifically, the developers. Once the vulnerability becomes known, a race begins
for the developer, who must protect users. Zero-day attacks are generally not used to attack legacy
applications. Memory errors are indicative of a buffer overflow attack.
C: 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. XSS attacks are not used to attack legacy applications.
Memory errors are indicative of a buffer overflow attack.
D: The application is a legacy application. It is therefore unlikely to have an add-on. The question states
that the application often stops running due to a memory error. Memory errors are indicative of a buffer
overflow attack.http://searchsecurity.techtarget.com/definition/buffer-overflow
http://en.wikipedia.org/wiki/Cross-site_scripting
http://www.pctools.com/security-news/zero-day-vulnerability/