Chapter 5
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Security Threats to
Electronic Commerce
Electronic Commerce
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Security Overview
 Many
fears to overcome:
Intercepted e-mail messages is a concern
 Unauthorized access to business
information by a competitor
 Credit card information falling into the
wrong hands while typing during payment
processing

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Security Definition
 Computer
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security is the protection of
unauthorized access, use, alteration, or
destruction hardware, software, and data.
 Two types of computer security:
 Physical - protection of computing devices
using physical objects such as guards,
alarms, security doors, vaults, etc.
 Logical - protection through password,
firewall, and encryption are logical
solutions to security.
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Security Overview
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
Threat: Any act or object that poses a danger to
computer assets is known as a threat.

Countermeasures are procedures, either physical
or logical, that recognize, reduce, or eliminate a
threat

Threats that are low risk and unlikely to occur can be
ignored if the cost of protection is higher the asset
(hardware, software, data) value.
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Risk Management Model
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Computer Security Classification
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
Computer security can be classified into three
categories:

Secrecy
 Protecting against unauthorized data disclosure
and ensuring the authenticity of the data’s source
Integrity
 Preventing unauthorized data modification
Necessity
 Preventing data delays or denials (removal)


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Security Policy


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




A Security policy is a written statement describing what assets are to be
protected and why, who is responsible, which behaviors are acceptable or
not. Any organization involved in e-commerce, should have a security
policy in place.
Specific elements of a security policy addresses:
Authentication
 Who is trying to access the site?
Access Control
 Who is allowed to logon and access the site?
Secrecy
 Who is permitted to view selected information
Data integrity
 Who is allowed to change data?
Audit
 What and who causes selected events to occur, and when?
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Integrated Security


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Security policy should address an integrated
security of an organization.
Integrated security policy should address all security
measures in order to prevent unauthorized
disclosure, destruction, or modification of assets. It
includes:
 Physical security
 Network security
 Access authorizations
 Virus protection
 Disaster recovery
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Electronic Commerce Threats
 Secure
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electronic commerce include
protection of three assets in the “commerce
chain”.
 These are:
 Client computers
 Messages travelling from the client
computer to the Web server through the
Internet
 Web/Commerce servers
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Client Threats
 Active
Content

Java applets, Active X controls, JavaScript, and
VBScript, which are programs that interpret or
execute instructions embedded in downloaded
objects from a Web/commerce server

Malicious active content can be embedded into
seemingly innocuous Web pages

Cookies remember user names, passwords, and
other commonly referenced information
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Java and Java Applets
 Java
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is a high-level programming
language developed by Sun
Microsystems
 Java code embedded into appliances
can make them run more intelligently
 Largest use of Java is in Web pages as
Java Applets
 Java is Platform independent - will run
on any computer
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Java Applets



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
An applet is a program that executes within another program and
cannot execute directly on a computer
Once downloaded, a Java applet can run on a client computer, so
security violations can occur
Java sandbox security:
 Confines Java applet actions to a security model-defined set of
rules
 Rules apply to all untrusted applets, that have not been proven
secure
 Applets obeying sandbox rules can not perform file input, output,
or delete operations of the operating system.
Signed Java applets:
 Contain embedded digital signatures from a third party, which
serve as a proof of identity of the source of the applet.
 If the applet is signed, then it can be let out of sandbox to use the
full system resources
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JavaScript
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
JavaScript is a scripting language developed by
Netscape Corporation to enable Web page
designers to build active content.

When downloaded a Web page with embedded
JavaScript, it runs in the client computer and can
destroy hard disk, send back e-mail accounts to the
originating Web server, and so on. Having a secure
communication channel is not useful under this
condition
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ActiveX Controls
 ActiveX
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is an object, called a control, that
contains programs and properties that
perform certain tasks
 ActiveX controls only run on computers with
Windows 95, 98, or 2000
 Once downloaded, ActiveX controls execute
like any other program, having full access to
a computer’s resources reformatting a hard
disk, sending e-mail addresses, or shut down
the computer.
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Communication
Channel Threats

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Secrecy Threats:
 Secrecy is the prevention of unauthorized
information disclosure. It requires sophisticated
physical and logical mechanism to implement
 Theft of sensitive or personal information (e-mail
address, credit card number)is a significant
danger in e-commerce
 Sniffer programs can tap into a router of the
Internet and record information while it passes
from a client computer to a Web server.
 IP address of a computer is continually revealed
to a Web server while a user is on the web
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Communication
Channel Threats
 How
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to Hide an IP address from a Web site:
 A Web site called “Anonymizer” that
provides a measure of secrecy by hiding
the IP address of a client computer from
sites that a user visits.
 It requires that a users starts his/her visit
from the “anonymizer” home page:
http://www.anonymizer.com
 Anonymizer acts as a firewall and shields
private information from leaking out.
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Communication
Channel Threats
 Integrity
Threats:
Also known as active wiretapping
 Unauthorized party can alter data such as
changing the amount of a deposit or
withdrawal in bank transaction over the
Internet
 A hacker can create a mechanism such
that all transactions from a Web site
redirects to a fake location.

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Communication
Channel Threats
 Necessity
Threats:
Also known as delay or denial threats
 Disrupt normal computer processing

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 Deny
processing entirely
 Slow processing to intolerably slow speeds
such that customers get bored not to visit the
site anymore.
 Remove file entirely, or delete information from
a transmission or file
 Divert money from one bank account to
another
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Server Threats
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
The more complex a Web server software becomes,
the higher the probability that errors (bugs) exist in
the code - security holes through which hackers can
access.

Web servers run at various privilege levels:
 Highest levels provide greatest access and
flexibility to a Web user (from a browser)
 Lowest levels provide a logical fence around a
running program
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Server Threats
 Secrecy
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violations occur when the contents
of a server’s folder names are revealed to a
Web browser
 Web site administrators can turn off the
“Allow Directory Browsing” feature to avoid
secrecy violations
 Cookies requested by a Web server,
containing a user’s Userid and Password in a
client computer, should never be transmitted
unprotected
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Server Threats
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Displayed Folder Names
Figure 5-9
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Server Threats
 One
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of the most sensitive files on a
Web server holds the username and
password pairs
 The
Web server administrator is
responsible for ensuring that this, and
other sensitive files, are secure
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Database Threats
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
A company database systems store data on user,
products, and orders for e-commerce

In addition, a company’s valuable and private
information could be stored in a company database

Security in a database is often enforced through
defining the user “privileges” which must be enforced

Some databases are inherently insecure and rely on
the Web server to enforce security measures
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Other Threats
 Common
Gateway Interface (CGI)
Threats
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CGIs are programs that present a security
threat if misused
 CGI programs can reside almost
anywhere on a Web server and therefore
are often difficult to track down
 CGI scripts do not run inside a sandbox,
unlike JavaScript
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