A security administrator looking through IDS logs notices the following entry: (where email=joe@joe.com and passwd= `or 1==1′)
Which of the following attacks had the administrator discovered?

A.
SQL injection

B.
XML injection

C.
Cross-site script

D.
Header manipulation

Explanation:
The code in the question is an example of a SQL Injection attack. The code `1==1′ will always provide a value of true. This can be included in statement designed
to return all rows in a SQL table.

SQL injection is a code injection technique, used to attack data-driven applications, in which malicious SQL statements are inserted into an entry field for execution
(e.g. to dump the database contents to the attacker). SQL injection must exploit a security vulnerability in an application’s software, for example, when user input is
either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and unexpectedly executed. SQL
injection is mostly known as an attack vector for websites but can be used to attack any type of SQL database.
Incorrect Answers:
A: 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. The code in this question in not used for an XSS attack. Therefore, this answer is incorrect.
B: When a web user takes advantage of a weakness with SQL by entering values that they should not, it is known as a SQL injection attack. Similarly, when the
user enters values that query XML (known as XPath) with values that take advantage of exploits, it is known as an XML injection attack. XPath works in a similar
manner to SQL, except that it does not have the same levels of access control, and taking advantage of weaknesses within can return entire documents. The best
way to prevent XML injection attacks is to filter the user’s input and sanitize it to make certain that it does not cause XPath to return more data than it should. The
code in this question in not XML code. This is therefore not an XML Injection attack.
D: Header manipulation is an attack on an application that access web pages or web services. It involves introducing unvalidated data in an HTTP response header
which can enable cache- poisoning, cross-site scripting, cross-user defacement, page hijacking, cookie manipulation or open redirect. The code in the question is
not the code you would expect to see in a header manipulation attack. This answer is therefore incorrect.

http://en.wikipedia.org/wiki/SQL_injection
http://en.wikipedia.org/wiki/Cross-site_scripting
Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, Sixth Edition, Sybex, Indianapolis, 2014, p 337