What
Is a Penetration Test?
A
penetration test is a subclass of ethical hacking; it comprises a set of
methods and procedures that aim at testing/protecting an organization’s
security. The penetration tests prove helpful in finding vulnerabilities in an
organization and check whether an attacker will be able to exploit them to gain
unauthorized access to an asset.
Vulnerability Assessments
versus Penetration Test
Oftentimes,
a vulnerability assessment is confused with a penetration test; however, these
terms have completely different meanings. In a vulnerability assessment, our
goal is to figure out all the vulnerabilities in an asset and document them
accordingly. In a penetration test, however, we need to simulate as an attacker
to see if we are actually able to exploit a vulnerability and document the
vulnerabilities that were exploited and the ones that turned out to be
false-positive.
Pre engagement
Before
you start doing a penetration test, there is whole lot of things you need to
discuss with clients. This is the phase where both the customer and a
representative from your company would sit down and discuss about the legal
requirements and the “rules of engagement.”
Rules of Engagement
Every
penetration test you do would comprise of a rules of engagement, which
basically defines how a penetration test would be laid out, what methodology
would be used, the start and end dates, the milestones, the goals of the penetration
test, the liabilities and responsibilities, etc. All of them have to be
mutually agreed upon by both the customer and the representative before the
penetration test is started. Following are important requirements that are
present in almost every ROE:
- A proper “permission to hack” and a “nondisclosure” agreement should be signed by both the parties.
- The scope of the engagement and what part of the organization must be tested.
- The project duration including both the start and the end date.
- The methodology to be used for conducting a penetration test.
- The goals of a penetration test.
- The allowed and disallowed techniques, whether denial-of-service testing should be performed or not.
- The liabilities and responsibilities, which are decided ahead of time. As a penetration tester you might break into something that should not be accessible, causing a denial of service also, you might access sensitive information such as credit cards. Therefore, the liabilities should be defined prior to the engagement.
Milestones
Before starting a
penetration test, it’s good practice to set up milestones so that your project
is delivered as per the dates given in the rules of engagement.
You can use either a
GANTT chart or a website like Basecamp that helps you set up milestones to keep
track of your progress. The following is a chart that defines the milestones
followed by the date they should be accomplished.
Penetration
Testing Methodologies
In every penetration
test, methodology and the reporting are the most important steps. Let’s first
talk about the methodology. There are several different types of penetration
testing methodologies that address how a penetration test should be performed.
Some of them are discussed in brief next.
OSSTMM
An open-source
security testing methodology manual (OSSTMM) basically includes almost all the
steps involved in a penetration test. The methodology employed for penetration
test is concise yet it’s a cumbersome process which makes it difficult to
implement it in our everyday life. Penetration tests, despite being tedious,
demands a great deal of money out of company’s budgets for their completion
which often are not met by a large number of organizations.
NIST
NIST, on the other
hand, is more comprehensive than OSSTMM, and it’s something that you would be
able to apply on a daily basis and in short engagements. The screenshot
indicates the four steps of the methodology, namely, planning, discovery,
attack, and reporting.
The testing starts
with the planning phase, where how the engagement is going to be
performed is decided upon. This is followed by the discovery phase,
which is divided into two parts—the first part includes information gathering,
network scanning, service identification, and OS detection, and the second part
involves vulnerability assessment.
After the discovery phase comes the attack phase,
which is the heart of every penetration test. If you are able to compromise a
target and a new host is discovered, in case the system is dual-homed or is
connected with multiple interfaces, you would go back to step 2, that is,
discovery, and repeat it until no targets are left. The indicating arrows in
the block phase and the attack phase to the reporting phase indicate that you
plan something and you report it—you attack a target and report the results.
The organization also has a more detailed
version of the chart discussed earlier, which actually explains more about the attack
phase. It consists of things such as “gaining access,” “escalating
privileges,” “system browsing,” and “install additional tools.” We will go
through each of these steps in detail in the following articles.
OWASP
As you might have
noticed, both the methodologies focused more on performing a network
penetration test rather than something specifically built for testing web
applications. The OWASP testing methodology is what we follow for all “application
penetration tests” we do here at the RHA InfoSEC. The OWASP testing guide
basically contains almost everything that you would test a web application for.
The methodology is comprehensive and is designed by some of the best web
application security researchers.
Categories
of Penetration Test
When the scope of the
penetration test is defined, the category/type of the penetration test
engagement is also defined along with it. The entire penetration test can be
Black Box, White Box, or Gray Box depending upon what the organization wants to
test and how it wants the security paradigm to be tested.
Black Box
A black box
penetration test is where little or no information is provided about the
specified target. In the case of a network penetration test this means that the
target’s DMZ, target operating system, server version, etc., will not be
provided; the only thing that will be provided is the IP ranges that you would
test. In the case of a web application penetration test, the source code of the
web
application will not
be provided. This is a very common scenario that you will encounter when
performing an external penetration test.
White Box
A white box
penetration test is where almost all the information about the target is
provided. In the case of a network penetration test, information on the
application running, the corresponding versions, operating system, etc., are
provided. In the case of a web application penetration test the application’s
source code is provided, enabling us to perform the static/dynamic “source code
analysis.” This scenario is very common in internal/onsite penetration tests,
since organizations are concerned about leakage of information.
Gray Box
In a gray box test,
some information is provided and some hidden. In the case of a network
penetration test, the organization provides the names of the application
running behind an IP; however, it doesn’t disclose the exact version of the services
running. In the case of a web application penetration test, some extra
information, such as test accounts, back end server, and databases, is
provided.
Types of Penetration
Tests
There are several
types of penetration tests; however, the following are the ones most commonly
performed:
Network Penetration
Test
In a network
penetration test, you would be testing a network environment for potential
security vulnerabilities and threats. This test is divided into two categories:
external and internal penetration tests.
An external
penetration test would involve testing the public IP addresses, whereas in an
internal test, you can become part of an internal network and test that
network. You may be provided VPN access to the network or would have to
physically go to the work environment for the penetration test depending upon
the engagement rules that were defined prior to conducting the test.
Web Application
Penetration Test
Web application
penetration test is very common nowadays, since your application hosts critical
data such as credit card numbers, usernames, and passwords; therefore this type
of penetration test has become more common than the network penetration test.
Mobile Application
Penetration Test
The mobile
application penetration test is the newest type of penetration test that has
become common since almost every organization uses Android- and iOS-based
mobile applications to provide services to its customers. Therefore,
organizations want to make sure that their mobile applications are secure
enough for users to rely on when providing personal information when using such
applications.
Social Engineering
Penetration Test
A social engineering
penetration test can be part of a network penetration test. In a social
engineering penetration test the organization may ask you to attack its users.
This is where you use speared phishing attacks and browser exploits to trick a
user into doing things they did not intend to do.
Physical Penetration
Test
A physical
penetration test is what you would rarely be doing in your career as a
penetration tester. In a physical penetration test, you would be asked to walk
into the organization’s building physically and test physical security controls
such as locks and RFID mechanisms.
Report
Writing
In any penetration
test, the report is the most crucial part. Writing a good report is key to
successful penetration testing. The following are the key factors to a good
report:
Your report should be
simple, clear, and understandable. Presentation of the report is also
important. Headers, footers, appropriate fonts, well-spaced margins, etc.,
should be created/selected properly and with great care. For example, if you
are using a red font for the heading, every heading in the document should be
in that style. The report should be well organized. Correct spelling and
grammar is important too. A misspelled word leaves a very negative impact upon
the person who is reading your report. So, you should make sure that you
proofread your report and perform spell-checks before submitting it to the
client. Always make sure that you use a consistent voice and style in writing a
report. Changing the voice would create confusion in the reader; so you should
choose one voice and style and stick to it throughout your report.
Make sure you spend
time on eliminating false-positives (vulnerabilities that are actually not
present), because false-negatives will always be there no matter what you do.
Eliminating the false-positives would enhance the credibility of the report. Perform
a detailed analysis of the vulnerability to find out its root cause. A
screenshot of a RAW http request or the screenshot that demonstrates the
evidence of the finding would give a clear picture to the developer of the
status.
Understanding the
Audience
Understanding the
audience that would be reading your penetration testing report is a very
crucial part of the penetration test. We can divide the audience into three
different categories:
1. Executive class
2. Management class
3. Technical class
While writing a
report, you must understand which audience would read which part of your
report; for example, the company’s CEO would not be interested in what exploit
you used to gain access to a particular machine, but on the flip side, your
developers will probably not be interested in the overall risks and potential
losses to the company; instead, they would be interested in fixing the code and
therefore in reading about detailed findings. Let’s briefly talk about the
three classes.
Executive Class
This category
includes the CEOs of the company. Since they have a very tedious schedule and
most of the times have less technical knowledge, they would end up reading a
very small portion of the report, specifically the executive summary,
remediation report, etc., which we will discuss later in this article.
Management Class
Next, we have the
management class, which includes the CISOs and CISSPs of the company. Since
they are the ones who are responsible for implementing the security policy of
the company, hey would probably be a bit more interested in reading about
overall strengths and weaknesses, the remediation report, the vulnerability
assessment report, etc.
Technical Class
This class includes
the security manager and developers, who would be interested in reading your
report thoroughly. They would investigate your report as they are responsible
for patching the weaknesses found and for making sure that the necessary
patches are implemented.
Writing
Reports
Now we are going to
get into the essentials of the reporting phase, which will teach you about the
structure of a report. We have discussed what a good report should look like. I
pointed out that knowing your audience was essential. One of the key factors
about a good report is that it should meet the needs for each audience and be
presented in a clear and understandable manner. The next major part of writing
a report is the analysis, where we perform risk assessment and calculate the
overall risk to the organization based upon our findings; along with this, your
report should also provide remediation on how the risk can be averted.
Structure
of a Penetration Testing Report
Let’s look step by
step on how a good report should be laid out. At the end of this article, I
have provided links to some of the best reports which have been provided to the
local mass.
Cover Page
We start with the
cover page; this is where you would include details such as your company logo,
title, and a short description about the penetration test. I would suggest you
hire a good designer and work on a professional and appealing cover page
because if your cover page looks great, it would make a good first impression
upon the customer reading it.
Table of Contents
On the very next
page, you should have an index so that the audience interested in reading a
particular portion of the report can easily skip to that portion.
Executive Summary
As the name suggests,
an executive summary is the portion that is specifically addressed to
executives such as the CEO or the CIO of the company. The executive summary is
the most essential part of a penetration testing report; a good executive
summary can make all the difference between a good report and a bad one.
Since the executive summary is specifically
written to address the nontechnical audience, you should make sure that it’s
presented in such a way that it’s easily comprehensible. Following are some of
the essential points that you should take into consideration while writing an
executive summary.
- Since executives are very busy, they have minimal time to invest in reading your reports. Therefore you should make sure that your executive summary is precise and to the point.
- Your executive summary should start with defining the purpose of the engagement and how it was carried out. Things such as the scope should be defined but very precisely.
- Next, you should explain the results of the penetration test and the findings.
- Following this, you should discuss the overall weaknesses in general and the countermeasures that were not implemented that caused the vulnerability in the first place.
- Next comes the analysis part; this is where you should write about the overall risk that was determined based upon our findings.
- And, finally, you should write about to what extent the risk would decrease after addressing the issues and implementing the appropriate countermeasures.
- The following is a point out of an executive summary. I would suggest you spend some time reviewing the essential points discussed and compare them with the executive summary that follows.
Next up we have the
remediation report, which contains the overall recommendations that once
implemented would increase the security of the organization. This is
specifically an area of interest for the management class, as they are the ones
that are going to enforce the security policies of an organization.
Vulnerability
Assessment Summary
Next, we have the
vulnerability assessment summary, sometimes referred to as “findings summary.”
This is where we present the findings from our engagement. Things such as the
overall strengths and weaknesses and risk assessment summary can also be included
under this section.
It always helps to
include charts in your report, which would give the audience a better
understanding of the vulnerabilities that were found. Security executives might
be interested in this portion of the report as they would
need to enforce the
countermeasures.
There are different
ways for representing vulnerability assessment outputs in the form of graphical
charts. Personally, I include two graphs; the first one classifies the
vulnerability assessment on the basis of the severity and the second one on
percentage.
Next, We suggest a
“vulnerabilities breakdown” chart, where We talk about the findings for a
particular host followed by the number of vulnerabilities that were found.
Tabular Summary
A tabular summary is
also a great way to present the findings of a vulnerability assessment to a
customer. vulnerability assessment based upon the number of live hosts and also
talks about the number of findings with high, moderate, or low risk.
Risk Assessment
Risk assessment as
defined before is the analysis part of the report. It is very crucial for the
customer because they would want to know the intensity of the damage the
vulnerabilities are likely to cause; similarly, the security executives would
also want to know how their team is performing.
Risk Assessment
Matrix
When we talk about
risk assessment analysis in terms of a penetration test, we have to compare the
“likelihood of the occurring” and the “impact caused by the occurring.”
After including the
risk assessment matrix, you should write a line or two describing the total
risk. Based upon the comparison of the vulnerabilities that were determined,
their likelihood and their impact we conclude the overall risk is high and the
risk percentage was determined to be 82%.
Methodology
We have discussed a
wide variety of methodologies and standards of penetration testing, such as
OSSTMM, NIST, and OWASP. I would also like to include the methodology that was
followed for conducting the penetration test, though its inclusion in the
report is optional, it could add great value to your penetration report. In a
scenario where you have been asked to follow a certain standard, talking about
the methodology and its steps is a good idea.
Detailed Findings
This is where you
address the technical audience, specifically the security manager and the
developers, also, this is where you are allowed to talk in depth about how the
vulnerabilities were discovered, the root causes of the vulnerabilities, the
associated risks, and the necessary recommendations.
Let’s now briefly
talk about four essentials that should be included in the “Detailed Findings”
section.
Description
This is where you
talk about the vulnerability itself; a brief explanation should be provided in
this section.
Explanation
This is the section
where you reveal where the vulnerability was found, how it was found, the root
cause of the vulnerability, the proof of concept, or the evidence of the
finding.
Risk
This is where you
talk about the risks and the likely impact that the vulnerability carries.
Recommendation
This is where you
address the developers on how to fix the vulnerability; you may also include
general suggestions to avoid that particular class of vulnerability in future.
In the “Description”
section we discussed the vulnerability. In the “Explanation” section, we talked
about where the vulnerability was found and what line of the programming code
is the root cause of the vulnerability. We then talked about general risks and
the impact and finally the general remediation to avoid vulnerabilities of a
similar class.
Reports
Now that you know the
basics and structure of how a penetration testing report is written, I would
urge you to spend some time reviewing the following penetration testing sample
reports.
- http://www.offensive-security.com/penetration-testing-sample-report.pdf
Conclusion
In this article, we
talked about basic terminologies that you will encounter on a daily basis as a
penetration tester. We discussed about the types of penetration tests and the
different penetration testing methodologies. We then talked about what makes a
good penetration testing report. We also looked at how a penetration test
report should be laid out in order to provide the target audience the necessary
information.