The following blog is going to outline some of the fundamental principles of
information security. The frameworks used to protect data and systems to the
elements of what exactly makes data secure.
The measures,
frameworks and protocols discussed throughout this room all play a small part
in "Defence in Depth."
Defence in Depth is the use of multiple
varied layers of security to an organisation's systems and data in the hopes
that multiple layers will provide redundancy in an organisation's security
perimeter.
The CIA Triad
The CIA triad is an information security model that is
used in consideration throughout creating a security policy. This model has an
extensive background, ranging from being used in 1998.
This
history is because the security of information (information security) does not
start and/or end with cybersecurity, but instead, applies to scenarios like
filing, record storage, etc.
Consisting of three sections:
Confidentiality, Integrity and Availability (CIA), this model has quickly
become an industry standard today. This model should help determine the value
of data that it applies to, and in turn, the attention it needs from the
business.
The CIA triad is unlike a traditional model where
you have individual sections; instead, it is a continuous cycle. Whilst the
three elements to the CIA triad can arguably overlap, if even just one element
is not met, then the other two are rendered useless (similar to the fire
triangle). If a security policy does not answer these three sections, it is
seldom an effective security policy.
Whilst the three
elements to the CIA triad are arguably self-explanatory, let's explore
these and contextualise them into cybersecurity.
Confidentiality
This element is the protection of data from unauthorized access and
misuse. Organisations will always have some form of sensitive data
stored on their systems. To provide confidentiality is to protect this data
from parties that it is not intended for.
There are many
real-world examples for this, for example, employee records and accounting
documents will be considered sensitive. Confidentiality will be provided in
the sense that only HR administrators will access employee records, where
vetting and tight access controls are in place. Accounting records are less
valuable (and therefore less sensitive), so not as stringent access controls
would be in place for these documents. Or, for example, governments using a
sensitivity classification rating system (top-secret, classified,
unclassified)
Integrity
The CIA triad element of integrity is the
condition where information is kept accurate and consistent unless authorized
changes are made. It is possible for the information to change because of
careless access and use, errors in the information system, or unauthorized
access and use. In the CIA triad, integrity is maintained when the information
remains unchanged during storage, transmission, and usage not involving
modification to the information. Steps must be taken to ensure data cannot be
altered by unauthorised people (for example, in a breach of
confidentiality).
Many defences to ensure integrity can be
put in place. Access control and rigorous authentication can help prevent
authorized users from making unauthorized changes.
Hash verifications and digital signatures can help ensure that
transactions are authentic and that files have not been modified or
corrupted.
Availability
In order for data to be useful, it must be available and accessible by
the user.
The main concern in the CIA triad is that the information
should be available when authorised users need to access it.
Availability
is very often a key benchmark for an organisation. For example, having 99.99%
uptime on their websites or systems (this is laid out in
Service Level Agreements). When a system is unavailable, it often results in damage to an
organisations reputation and loss of finances. Availability is achieved
through a combination of many elements, including:
Having reliable and well-tested hardware for their information technology
servers (i.e. reputable servers)
Having redundant technology and services in the case of failure of the primary
Implementing well-versed security protocols to protect technology and services
from attack
1) What element of the CIA triad ensures that data cannot be altered by
unauthorised people?
Ans - Integrity
2) What element of the CIA triad ensures that data is available?
Ans - Availability
3) What element of the CIA triad ensures that data is only accessed by
authorised people?
Ans - confidentiality
Principles of Privileges
It is vital to administrate and correctly define the various levels of
access to an information technology system individuals require.
The levels of access given to individuals are determined on two
primary factors:
- The individual's role/function within the organisation
- The sensitivity of the information being stored on the system
Two key concepts are used to assign and manage the access rights
of individuals, two key concepts are used:
Privileged Identity Management (PIM) and Privileged Access Management (or PAM for
short).
Initially, these two concepts can seem to overlap;
however, they are different from one another. PIM is used to translate
a user's role within an organisation into an access role on a system. Whereas
PAM is the management of the privileges a system's access role has,
amongst other things.
What is essential when discussing
privilege and access controls is the principle of least privilege. Simply,
users should be given the minimum amount of privileges, and only those that
are absolutely necessary for them to perform their duties. Other people should
be able to trust what people write to.
As we previously
mentioned, PAM incorporates more than assigning access. It also encompasses
enforcing security policies such as password management, auditing policies and
reducing the attack surface a system faces.
1) What does the acronym "PIM" stand for?
Ans- Privileged identity management
2) What does the acronym "PAM" stand for?
Ans - Privileged Access Management
3) If you wanted to manage the privileges a system access role had, what
methodology would you use?
Ans - PAM
4) If you wanted to create a system role that is based on a users
role/responsibilities with an organisation, what methodology is this?
Ans - PIM
Security Models Continued
Before discussing security models further, let's recall the three
elements of the CIA triad: Confidentiality, Integrity and Availability. We've previously outlined what these elements are and their importance.
However, there is a formal way of achieving this.
According
to a security model, any system or piece of technology storing information is
called an information system, which is how we will reference systems and
devices in this task.
Let's explore some popular and
effective security models used to achieve the three elements of the
CIA triad.
The Bell-La Padula Model
The Bell-La Padula Model
is used to achieve confidentiality. This model has a few assumptions, such as an organisation's hierarchical
structure it is used in, where everyone's responsibilities/roles are
well-defined.
The model works by granting access to pieces of
data (called objects) on a strictly need to know basis. This model uses the
rule "no write down, no read up".
| Advantages | Disadvantages |
|---|---|
| Policies in this model can be replicated to real-life organisations hierarchies (and vice versa) | Even though a user may not have access to an object, they will know about its existence -- so it's not confidential in that aspect. |
| Simple to implement and understand, and has been proven to be successful. | The model relies on a large amount of trust within the organisation. |
The Bell LaPadula Model is popular within organisations such as
governmental and military. This is because members of the organisations are
presumed to have already gone through a process called vetting. Vetting is a
screening process where applicant's backgrounds are examined to establish the
risk they pose to the organisation. Therefore, applicants who are successfully
vetted are assumed to be trustworthy - which is where this model fits in.
Biba Model
The Biba model is arguably the equivalent of the Bell-La Padula model
but for the integrity of the CIA triad.
This model applies the rule to objects (data) and subjects
(users) that can be summarised as "no write up, no read down". This rule means
that subjects can create or write content to objects at or below their level
but can only read the contents of objects above the subject's level.
Let's
compare some advantages and disadvantages of this model in the table below:
| Advantages | Disadvantages |
|---|---|
| This model is simple to implement. | There will be many levels of access and objects. Things can be easily overlooked when applying security controls. |
| Resolves the limitations of the Bell-La Padula model by addressing both confidentiality and data integrity. | Often results in delays within a business. For example, a doctor would not be able to read the notes made by a nurse in a hospital with this model. |
The Biba model is used in organisations or situations where integrity is
more important than confidentiality. For example, in software development,
developers may only have access to the code that is necessary for their job.
They may not need access to critical pieces of information such as databases,
etc.
1) What is the name of the model that uses the rule "can't read up, can
read down"?
Ans - The Bell-La Padula Model
2) What is the name of the model that uses the rule "can read up, can't
read down"?
Ans - the biba model
3) If you were a military, what security model would you use?
Ans - The Bell-La Padula Model
4) If you were a software developer, what security model would the company
perhaps use?
Ans - the biba model
Threat Modelling & Incident Response
Threat modelling is the process of reviewing, improving, and testing the
security protocols in place in an
organisation's information technology infrastructure and
services.
A critical stage of the threat
modelling process is identifying likely threats that an application or system
may face, the vulnerabilities a system or application may be vulnerable
to.
The threat modelling process is very similar to a risk assessment
made in workplaces for employees and customers. The principles all return
to:
- Preparation
- Identification
- Mitigations
- Review
It is, however, a complex process that needs constant review and discussion
with a dedicated team. An effective threat model includes:
- Threat intelligence
- Asset identification
- Mitigation capabilities
- Risk assessment
To help with this, there are frameworks such as STRIDE
(Spoofing, identity, Tampering with data, Repudiation threats, Information
disclosure, Denial of Service and Elevation of privileges) and
PASTA (Process for Attack Simulation and Threat Analysis) infosec never tasted so good!. Let's detail STRIDE below.
STRIDE, authored by two Microsoft security researchers in 1999 is still very
relevant today. STRIDE includes six main principles, which I have detailed in
the table below:Know About Principles Of Security
| Principle | Description |
|---|---|
| Spoofing | This principle requires you to authenticate requests and users accessing a system. Spoofing involves a malicious party falsely identifying itself as another. Access keys (such as API keys) or signatures via encryption helps remediate this threat. |
| Tampering | By providing anti-tampering measures to a system or application, you help provide integrity to the data. Data that is accessed must be kept integral and accurate. For example, shops use seals on food products. |
| Repudiation | This principle dictates the use of services such as logging of activity for a system or application to track. |
| Information Disclosure | Applications or services that handle information of multiple users need to be appropriately configured to only show information relevant to the owner is shown. |
| Denial of Service | Applications and services use up system resources, these two things should have measures in place so that abuse of the application/service won't result in bringing the whole system down. |
| Elevation of Privilege | This is the worst-case scenario for an application or service. It means that a user was able to escalate their authorization to that of a higher level i.e. an administrator. This scenario often leads to further exploitation or information disclosure. |
A breach of security is known as an incident. And despite all rigorous
threat models and secure system designs, incidents do happen. Actions taken to
resolve and remediate the threat are known as Incident Response
(IR) and are a whole career path in cybersecurity.
Incidents are classified using a rating of urgency and
impact. Urgency will be determined by the type of attack faced, where the
impact will be determined by the affected system and what impact that has on
business operations.
An incident is responded to by a Computer Security Incident
Response Team (CSIRT) which is prearranged group of employees with technical
knowledge about the systems and/or current incident. To successfully solve an
incident, these steps are often referred to as the six phases of Incident
Response that takes place, listed in the table below:
| Action | Description |
|---|---|
| Preparation | Do we have the resources and plans in place to deal with the security incident? |
| Identification | Has the threat and the threat actor been correctly identified in order for us to respond to? |
| Containment | Can the threat/security incident be contained to prevent other systems or users from being impacted? |
| Information Disclosure | Applications or services that handle information of multiple users need to be appropriately configured to only show information relevant to the owner is shown. |
| Eradication | Remove the active threat. |
| Recovery | Perform a full review of the impacted systems to return to business as usual operations. |
| Lessons Learned | What can be learnt from the incident? I.e. if it was due to a phishing email, employees should be trained better to detect phishing emails. |
1) What model outlines "Spoofing"?
Ans - STRIDE
2) What does the acronym "IR" stand for?
Ans - incident response
3) You are tasked with adding some measures to an application to improve the integrity of data, what STRIDE principle is this?
Ans - Tampering
4) An attacker has penetrated your organisation's security and stolen data. It is your task to return the organisation to business as usual. What incident response stage is this?
Ans - Recovery
Disclaimer
All tutorials are for informational and educational purposes only and have been made using our own routers, servers, websites and other vulnerable free resources. we do not contain any illegal activity. We believe that ethical hacking, information security and cyber security should be familiar subjects to anyone using digital information and computers. Hacking Truth is against misuse of the information and we strongly suggest against it. Please regard the word hacking as ethical hacking or penetration testing every time this word is used. We do not promote, encourage, support or excite any illegal activity or hacking.
- Hacking Truth by Kumar Atul Jaiswal
