ISO/IEC TR 3445:2022

TECHNICAL ISO/IEC TR
REPORT 3445
First edition
2022-03
Information technology — Cloud
computing — Audit of cloud services
Reference number
ISO/IEC TR 3445:2022(E)
© ISO/IEC 2022

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ISO/IEC TR 3445:2022(E)
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© ISO/IEC 2022
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ISO/IEC TR 3445:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terms related to the use of audit and assessment . 1
3.2 Terms related to cloud service audit . 3
4 Abbreviated terms . 5
5 Overview of cloud computing and the activities of a cloud auditor .5
5.1 Overview of cloud computing. 5
5.1.1 General . 5
5.1.2 Cloud computing roles, sub-roles and activities . 6
5.2 Overview of the activities of a cloud auditor . 7
5.2.1 Cloud auditor . 7
5.2.2 Responsibilities of a cloud auditor . 8
5.2.3 Cloud auditor’s cloud computing activities . 9
5.2.4 Relationship of the cloud auditor to CSPs, CSCs, and other CSNs . 10
6 Overview of the audit of cloud services .10
6.1 General . 10
6.2 Objectives of an audit of cloud service . 11
6.2.1 General . 11
6.2.2 Audit objectives . 11
6.2.3 Audit boundaries .13
6.2.4 Relationship of an audit and the organization .13
6.3 Types of cloud audit . .15
6.3.1 Overview . 15
6.3.2 Internal audit .15
6.3.3 External audit . 16
6.3.4 Exemplary tests and audits . 17
6.3.5 Relationship between audit and assessment for cloud computing . 19
6.3.6 Relationships among audit processes and reports . 19
6.3.7 Conformity Assessment – Objectives and expectations . 24
6.4 Cloud audit and trust . 24
7 Audit specifications and challenges .25
7.1 Overview . 25
7.2 Establishing audit scope .25
7.3 Audit risk assessment . .25
7.3.1 General . 25
7.3.2 Risk assessment of cloud computing systems and legacy or non-cloud
computing system .26
7.4 Security controls assessment .26
7.5 Required laws, regulations, and government requirements . 27
7.6 Policies .28
7.6.1 General .28
7.6.2 Geolocation data .28
7.7 Cloud service agreement (CSA) .28
7.8 Cloud capabilities types, cloud service categories and key characteristics .29
7.9 Cross-cutting aspects . 31
7.10 Emerging technologies and cloud native . 31
7.11 Define metrics and security parameters . 32
7.12 Determining matrix . 33
7.13 Assessment of cloud governance . 33
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ISO/IEC TR 3445:2022(E)
7.14 Challenges of conducting an audit of cloud services . 33
7.14.1 General . 33
7.14.2 Third party auditability .33
7.14.3 Change management . 33
7.14.4 Patch management .34
7.14.5 Multi-tenant environment.34
7.14.6 Auditability and assurance .34
7.14.7 Availability requirement .34
8 Approaches to conducting audits .35
8.1 Typical Scenarios . 35
8.2 Cloud audit – opportunities and meeting objectives . 35
8.2.1 General . 35
8.2.2 Stakeholders and related activities on cloud audit .36
8.3 Processes – identify, analyse, evaluate . 36
8.4 Data flow – lifecycle - confidentiality, integrity, availability . 37
8.5 Automation of cloud service audits and assessments . 37
Annex A (informative) Sample list of standards and frameworks applicable to audit of
cloud services .39
Annex B (informative) Compilation of frameworks, schemes, and auditing programs for
certification, attestation and authorization which are relevant to cloud security . 44
Bibliography .49
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ISO/IEC TR 3445:2022(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see https://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 38, Cloud computing and distributed platforms.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
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ISO/IEC TR 3445:2022(E)
Introduction
This document provides an overview of the audit of cloud services. ISO/IEC 22123-1 defines the term
cloud auditor while ISO/IEC 17789 describes the cloud computing roles and sub-roles and activities
related to the audit of cloud services. ISO/IEC TR 23187 which describes the interactions between cloud
service partners (CSNs), cloud service customers (CSCs), and cloud service providers (CSPs) provides
some perspectives on the role and responsibilities of a cloud auditor. This is covered in part in Clause 5
as shown in Figure 1.
Figure 1 — Structure of the document
The structure of the document is as follows:
Clause 5 includes an overview of cloud computing and its major roles. This clause also covers the role of
cloud auditor, its responsibilities, and its relationship with other major cloud computing roles.
Clause 6 provides an overview of cloud service audit including an explanation of the relationship
between audit, assessment, compliance, evaluation, assurance and conformity assessment.
Clause 7 builds on the foundation information in Clause 5 to discuss audit specifications and the
challenges associated with a cloud audit.
Clause 8 covers approaches to conducting cloud audit.
Annex A provides information on International Standards relating to audit and frameworks for audit
schemes, certification and authorization.
Annex B is a compilation of available frameworks and standards which can be used for audit schemes,
for certification and for authorization.
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TECHNICAL REPORT ISO/IEC TR 3445:2022(E)
Information technology — Cloud computing — Audit of
cloud services
1 Scope
This document surveys aspects of the audit of cloud services including:
1) role and responsibilities of parties conducting audit and description of the interactions between
the CSC, CSP, and CSN;
2) approaches for conducting audits of cloud services to facilitate confidence in delivering and using
cloud services;
3) examples of available frameworks and standards which can be used for audit schemes, for
certification, and for authorization.
This document builds upon the cloud auditor role as defined in ISO/IEC 17789 and ISO/IEC 22123.
This document is applicable to all types and sizes of organizations that need to plan and conduct
internal or external audits, and that use, provide and support cloud services.
This document is not intended to describe certification or to identify controls that are published
elsewhere.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 22123-1:2021, Information technology — Cloud computing — Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 22123-1 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms related to the use of audit and assessment
3.1.1
assurance
activity resulting in a statement giving confidence that a product, process or service fulfils specified
requirement
[SOURCE: ISO/IEC Guide 2, 15.1]
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ISO/IEC TR 3445:2022(E)
3.1.2
attestation
issue of a statement, based on a decision, that the fulfilment of specified requirements has been
demonstrated
Note 1 to entry: The resulting statement, referred to in the source document as a “statement of conformity”, is
intended to convey the assurance (3.1.1) that the specified requirements have been fulfilled. Such an assurance
(3.1.1) does not, of itself, provide contractual or other legal guarantees.
Note 2 to entry: First-party attestation and third party attestation are distinguished by the terms declaration,
certification (3.1.4) and accreditation, but there is no corresponding term applicable to second party attestation.
[SOURCE: ISO/IEC 17000:2020, 7.3]
3.1.3
authorization
privileges that give access to designated activities
[SOURCE: ISO 11442:2006, 3.5]
3.1.4
certification
third party attestation (3.1.2) related to an object of conformity assessment (3.1.6), with the exception of
accreditation
[SOURCE: ISO/IEC 17000:2020, 7.6]
3.1.5
certification audit
audit (3.2.2) carried out by an auditing organization independent of the client and the parties that rely
on certification (3.1.4), for the purpose of certifying the client’s management system
Note 1 to entry: In the definitions which follow, the term “audit” has been used for simplicity to refer to third
party certification audit.
Note 2 to entry: Certification audits include initial, surveillance, re-certification audits, and can also include
special audits.
Note 3 to entry: Certification audits are typically conducted by audit teams of those bodies providing certification
(3.1.4) of conformity to the requirements of management system standards.
Note 4 to entry: A joint audit (3.2.11) is when two or more auditing organizations cooperate to audit a single
client.
Note 5 to entry: A combined audit (3.2.9) is when a client is being audited against the requirements of two or more
management systems standards together.
Note 6 to entry: An integrated audit is when a client has integrated the application of requirements of two or
more management systems standards into a single management system and is being audited against more than
one standard.
[SOURCE: ISO/IEC 17021-1:2015, 3.4]
3.1.6
conformity assessment
demonstration that specified requirements are fulfilled
Note 1 to entry: The process (3.1.8) of conformity assessment as described in the functional approach in Annex A
can have a negative outcome, i.e. demonstrating that the specified requirements are not fulfilled.
Note 2 to entry: Conformity assessment includes activities defined elsewhere in the source document, such as
but not limited to testing, inspection, validation, verification, certification (3.1.4), and accreditation.
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ISO/IEC TR 3445:2022(E)
Note 3 to entry: Conformity assessment is explained in Annex A as a series of functions. Activities contributing to
any of these functions can be described as conformity assessment activities.
Note 4 to entry: The source document does not include a definition of “conformity”. “Conformity” does not feature
in the definition of “conformity assessment”. Nor does the source document address the concept of compliance.
[SOURCE: ISO/IEC 17000:2020, 4.1]
3.1.7
compliance
compliant
meeting or exceeding all applicable requirements of a standard or other published set of requirements
[SOURCE: ISO/TR 19591:2018, 3.60]
3.1.8
process
set of interrelated or interacting activities that use inputs to deliver an intended result
[SOURCE: ISO 19011, 3.24]
3.2 Terms related to cloud service audit
3.2.1
assessment
process of collecting and analyzing outcomes to determine course of actions
3.2.2
audit
systematic, independent and documented process (3.1.8) for obtaining objective evidence (3.2.12) and
evaluating it objectively to determine the extent to which the audit criteria are fulfilled
Note 1 to entry: Internal audits (3.2.10), sometimes called first-party audits, are conducted by, or on behalf of, the
organization itself.
Note 2 to entry: External audits include those generally called second and third party audits. Second party audits
are conducted by parties having an interest in the organization, such as customers, or by other individuals on
their behalf. third party audits are conducted by independent auditing organizations, such as those providing
certification (3.1.4)/registration of conformity or governmental agencies.
[SOURCE: ISO 19011:2018, 3.1]
3.2.3
cloud service audit
audit (3.2.2) of the provision and use of one or more cloud services
Note 1 to entry: An audit of a cloud service can include cloud characteristics, cloud deployment, cross cutting
aspects and related management and security functions.
3.2.4
audit client
organization or person requesting an audit (3.2.2)
Note 1 to entry: In the case of internal audit (3.2.10), the audit client can also be the auditee (3.2.7) or the
individual(s) managing the audit programme. Requests for external audit can come from sources such as
regulators, contracting parties or potential or existing clients.
[SOURCE: ISO 19011:2018, 3.12]
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ISO/IEC TR 3445:2022(E)
3.2.5
audit programme
arrangements for a set of one or more audits (3.2.2) planned for a specific time frame and directed
towards a specific purpose
[SOURCE: ISO 19011:2018, 3.4]
3.2.6
audit scope
extent and boundaries of an audit (3.2.2)
Note 1 to entry: the audit scope generally includes a description of the physical and virtual-locations, functions,
organizational units, activities, and processes, as well as the time period covered.
Note 2 to entry: A virtual location is where an organization performs work or provides a service using an on-line
environment allowing individuals irrespective of physical locations to execute processes.
[SOURCE: ISO 19011:2018, 3.5]
3.2.7
auditee
organization as a whole or parts thereof being audited
[SOURCE: ISO 19011:2018, 3.13]
3.2.8
auditor
person who conducts an audit (3.2.2)
[SOURCE: ISO 9000:2015, 3.13.15]
3.2.9
combined audit
audit (3.2.1) carried out together at a single auditee (3.2.7) on two or more management systems
Note 1 to entry: When two or more discipline-specific management systems are integrated into a single
management system this is known as an integrated management system.
[SOURCE: ISO 9000:2015, 3.13.2, modified]
3.2.10
internal audit
audit (3.2.2) conducted by, or on behalf of, an organization itself for management review and other
internal purposes, and which can form the basis for an organization’s self-declaration of conformity
Note 1 to entry: In many cases, particularly in smaller organizations, independence can be demonstrated by the
freedom from responsibility for the activity being audited.
[SOURCE: ISO 22300:2021, 3.1.134]
3.2.11
joint audit
audit (3.2.2) carried out at a single auditee (3.2.7) by two or more auditing organizations
[SOURCE: ISO 9000:2015, 3.13.3]
3.2.12
objective evidence
data supporting the existence or verity of something
Note 1 to entry: objective evidence can be obtained through observation, measurement, test or by other means.
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ISO/IEC TR 3445:2022(E)
Note 2 to entry: objective evidence for the purpose of the audit (3.2.2) generally consists of records, statements
of fact, or other information which are relevant to the audit criteria and verifiable.
[SOURCE: ISO 9000:2015, 3.8.3]
3.2.13
party
natural person or legal person, whether or not incorporated, or a group of either
[SOURCE: ISO/IEC 22123-1:2021, 3.4.1]
4 Abbreviated terms
BCR binding corporate rules
Cloud SLA cloud service level agreement
CSA cloud service agreement
CSC cloud service customer
CSN cloud service partner
CSP cloud service provider
CSU cloud service user
FISMA The Federal Information Security Modernization Act of 2014 (FISMA 2014) (US)
GDPR General Data Protection Regulation (EU GDPR)
HSPD-12 Homeland Security Presidential Directive 12 (US)
ISMS information security management system
IT information technology
LGPD Brazil’s Lei Geral de Proteção de Dados
PCIDSS Payment Card Industry Data Security Standard
PIA Privacy impact assessment
PIMS Privacy information management system
SDOC Suppliers Declaration of Conformity
SLO cloud service level objective
SQO cloud service qualitative objective
5 Overview of cloud computing and the activities of a cloud auditor
5.1 Overview of cloud computing
5.1.1 General
Cloud computing, as defined in ISO/IEC 22123-1:2021, 3.2.1, is a paradigm for enabling network access
to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning
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ISO/IEC TR 3445:2022(E)
and administration on-demand. The cloud computing paradigm is comprised of cloud computing roles
and activities, cloud capabilities types and cloud service categories, cloud deployment models, key
characteristics and cross cutting aspects as shown in Figure 2.
Figure 2 — Overview of cloud computing
5.1.2 Cloud computing roles, sub-roles and activities
In the context of cloud computing and of particular importance to this document is the clarification of
the different roles and their activities. ISO/IEC 22123-1 identifies the major roles of cloud computing
and ISO/IEC 17789 expands on the roles to include sub-roles activities, and their relationship to the
functional components and functional layers of cloud computing.
The major cloud computing roles are:
— Cloud service customer (CSC) is a party which is in a business relationship for the purpose of using
cloud services.
— Cloud
...