IT AUDITMETHODOLOGIES

IT Audit Methodologies

• CobiT• BS 7799 - Code of Practice (CoP)• BSI - IT Baseline Protection Manual• ITSEC• Common Criteria (CC)

Main Areas of Use

• IT Audits• Risk Analysis• Health Checks (Security Benchmarking)• Security Concepts• Security Manuals / Handbooks

Security Definition

• Confidentiality• Integrity

– Correctness– Completeness

• Availability

CobiT

• Governance, Control & Audit for IT• Developed by ISACA• Releases

– CobiT 1: 1996• 32 Processes• 271 Control Objectives

– CobiT 2: 1998• 34 Processes• 302 Control Objectives

CobiT - Model for IT Governance

• 36 Control models used as basis:– Business control models (e.g. COSO)– IT control models (e.g. DTI‘s CoP)

• CobiT control model covers:– Security (Confidentiality, Integrity, Availability)– Fiduciary (Effectiveness, Efficiency, Compliance,

Reliability of Information)– IT Resources (Data, Application Systems,

Technology, Facilities, People)

CobiT - Framework

CobiT - Structure

• 4 Domains– PO - Planning & Organisation

• 11 processes (high-level control objectives)– AI - Acquisition & Implementation

• 6 processes (high-level control objectives)– DS - Delivery & Support

• 13 processes (high-level control objectives)– M - Monitoring

• 4 processes (high-level control objectives)

PO - Planning and Organisation

• PO 1 Define a Strategic IT Plan• PO 2 Define the Information Architecture• PO 3 Determine the Technological Direction• PO 4 Define the IT Organisation and Relationships• PO 5 Manage the IT Investment• PO 6 Communicate Management Aims and Direction• PO 7 Manage Human Resources• PO 8 Ensure Compliance with External Requirements• PO 9 Assess Risks• PO 10 Manage Projects• PO 11 Manage Quality

AI - Acquisition and Implementation

• AI 1 Identify Solutions• AI 2 Acquire and Maintain Application

Software• AI 3 Acquire and Maintain Technology

Architecture• AI 4 Develop and Maintain IT Procedures• AI 5 Install and Accredit Systems• AI 6 Manage Changes

DS - Delivery and Support

• DS 1 Define Service Levels• DS 2 Manage Third-Party

Services• DS 3 Manage Performance

and Capacity

• DS 4 Ensure Continuous Service

• DS 5 Ensure Systems Security

• DS 6 Identify and Attribute Costs

• DS 7 Educate and Train Users

DS 8 Assist and Advise IT

Customers

DS 9 Manage the Configuration

DS 10 Manage Problems and

Incidents

DS 11 Manage Data

DS 12 Manage Facilities

DS 13 Manage Operations

M - Monitoring

• M 1 Monitor the Processes• M 2 Assess Internal Control Adequacy• M 3 Obtain Independent Assurance• M 4 Provide for Independent Audit

CobiT - IT Process Matrix

Information Criteria

– Effectiveness– Efficiency– Confidentiali

ty– Integrity– Availability– Compliance– Reliability

IT ResourcesPeopleApplicationsTechnologyFacilitiesData

CobiT - Summary

• Mainly used for IT audits, incl. security aspects• No detailed evaluation methodology described• Developed by international organisation (ISACA)• Up-to-date: Version 2 released in 1998• Only high-level control objectives described• Detailed IT control measures are not documented• Not very user friendly - learning curve!• Evaluation results not shown in graphic form

BS 7799 - Security Baseline Controls

• 10 control categories• 32 control groups• 109 security controls• 10 security key controls

BS 7799 - Control Categories

• Information security policy• Security organisation• Assets classification & control• Personnel security• Physical & environmental security• Computer & network management

BS 7799 - Control Categories

• System access control• Systems development & maintenance• Business continuity planning• Compliance

BS7799 - 10 Key Controls

• Information security policy document• Allocation of information security

responsibilities• Information security education and training• Reporting of security incidents• Virus controls

BS7799 - 10 Key Controls

• Business continuity planning process• Control of proprietary software copying• Safeguarding of organizational records• Data protection• Compliance with security policy

BS7799 - Summary

• Main use: Security Concepts & Health Checks• No evaluation methodology described• British Standard, developed by UK DTI• Certification scheme in place (c:cure)• BS7799, Part1, 1995 is being revised in 1999• Lists 109 ready-to-use security controls• No detailed security measures described• Very user friendly - easy to learn

BSI - Structure

• IT security measures– 7 areas– 34 modules (building blocks)

• Safeguards catalogue– 6 categories of security measures

• Threats catalogue– 5 categories of threats

BSI - Security Measures (Modules)

• Protection for generic components• Infrastructure• Non-networked systems• LANs• Data transfer systems• Telecommunications• Other IT components

BSI - Generic Components

• 3.1 Organisation

• 3.2 Personnel

• 3.3 Contingency Planning

• 3.4 Data Protection

BSI - Infrastructure

• 4.1 Buildings

• 4.2 Cabling

• 4.3 Rooms

• 4.3.1 Office

• 4.3.2 Server Room

• 4.3.3 Storage Media Archives

• 4.3.4 Technical Infrastructure Room

• 4.4 Protective cabinets

• 4.5 Home working place

BSI - Non-Networked Systems

• 5.1 DOS PC (Single User)

• 5.2 UNIX System

• 5.3 Laptop

• 5.4 DOS PC (multiuser)

• 5.5 Non-networked Windows NT computer

• 5.6 PC with Windows 95

• 5.99 Stand-alone IT systems

BSI - LANs

• 6.1 Server-Based Network

• 6.2 Networked Unix Systems

• 6.3 Peer-to-Peer Network

• 6.4 Windows NT network

• 6.5 Novell Netware 3.x

• 6.6 Novell Netware version 4.x

• 6.7 Heterogeneous networks

BSI - Data Transfer Systems

• 7.1 Data Carrier Exchange

• 7.2 Modem

• 7.3 Firewall

• 7.4 E-mail

BSI - Telecommunications

• 8.1 Telecommunication system

• 8.2 Fax Machine

• 8.3 Telephone Answering Machine

• 8.4 LAN integration of an IT system via ISDN

BSI - Other IT Components

• 9.1 Standard Software

• 9.2 Databases

• 9.3 Telecommuting

BSI - Module „Data Protection“ (3.4)

• Threats - Technical failure:– T 4.13 Loss of stored data

• Security Measures - Contingency planning:– S 6.36 Stipulating a minimum data protection concept– S 6.37 Documenting data protection procedures– S 6.33 Development of a data protection concept

(optional)– S 6.34 Determining the factors influencing data

protection (optional)– S 6.35 Stipulating data protection procedures (optional)– S 6.41 Training data reconstruction

• Security Measures - Organisation:– S 2.41 Employees' commitment to data protection– S 2.137 Procurement of a suitable data backup system

BSI - Safeguards (420 safeguards)

• S1 - Infrastructure ( 45 safeguards)• S2 - Organisation (153 safeguards)• S3 - Personnel ( 22 safeguards)• S4 - Hardware & Software ( 83 safeguards)• S5 - Communications ( 62 safeguards)• S6 - Contingency Planning ( 55 safeguards)

BSI - S1-Infrastructure (45 safeguards)

• S 1.7 Hand-held fire extinguishers

• S 1.10 Use of safety doors

• S 1.17 Entrance control service

• S 1.18 Intruder and fire detection devices

• S 1.27 Air conditioning

• S 1.28 Local uninterruptible power supply [UPS]

• S 1.36 Safekeeping of data carriers before and after dispatch

BSI - Security Threats (209 threats)

• T1 - Force Majeure (10 threats)• T2 - Organisational Shortcomings (58 threats)• T3 - Human Errors (31 threats)• T4 - Technical Failure (32 threats)• T5 - Deliberate acts (78 threats)

IT Audit Methodoloies

BSI - T3-Human Errors (31 threats)

• T 3.1 Loss of data confidentiality/integrity as a result of IT user error

• T 3.3 Non-compliance with IT security measures

• T 3.6 Threat posed by cleaning staff or outside staff

• T 3.9 Incorrect management of the IT system

• T 3.12 Loss of storage media during transfer

• T 3.16 Incorrect administration of site and data access rights

• T 3.24 Inadvertent manipulation of data

• T 3.25 Negligent deletion of objects

BSI - Summary

• Main use: Security concepts & manuals• No evaluation methodology described• Developed by German BSI (GISA)• Updated version released each year• Lists 209 threats & 420 security measures• 34 modules cover generic & platform specific

security requirements

BSI - Summary

• User friendly with a lot of security details• Not suitable for security risk analysis• Results of security coverage not shown in graphic

form• Manual in HTML format on BSI web server• Manual in Winword format on CD-ROM

(first CD free, additional CDs cost DM 50.-- each)

• Paper copy of manual: DM 118.--

• Software ‚BSI Tool‘ (only in German): DM 515.--

ITSEC, Common Criteria

• ITSEC: IT Security Evaluation Criteria• Developed by UK, Germany, France, Netherl. and

based primarily on USA TCSEC (Orange Book)

• Releases– ITSEC: 1991– ITSEM: 1993 (IT Security Evaluation Manual)– UK IT Security Evaluation & Certification scheme:

1994

ITSEC, Common Criteria

• Common Criteria (CC)• Developed by USA, EC: based on ITSEC• ISO International Standard• Releases

– CC 1.0: 1996– CC 2.0: 1998– ISO IS 15408: 1999

ITSEC - Methodology

• Based on systematic, documented approach for security evaluations of systems & products

• Open ended with regard to defined set of security objectives– ITSEC Functionality classes; e.g. FC-C2– CC protection profiles

• Evaluation steps:– Definition of functionality– Assurance: confidence in functionality

ITSEC - Functionality

• Security objectives (Why)– Risk analysis (Threats, Countermeasures)– Security policy

• Security enforcing functions (What)– technical & non-technical

• Security mechanisms (How)• Evaluation levels

ITSEC - Assurance

• Goal: Confidence in functions & mechanisms• Correctness

– Construction (development process & environment)– Operation (process & environment)

• Effectiveness– Suitability analysis– Strength of mechanism analysis– Vulnerabilities (construction & operation)

CC - Security Concept

CC - Evaluation Goal

CC - Documentation

CC Part 1Introduction and ModelIntroduction to

Approach

Terms and Model

Requirements forProtection Profiles (PP)and Security Targets (ST)

CC Part 2Functional Requirements

Functional Classes

Functional Families

FunctionalComponents

Detailed Requirements

CC Part 3Assurance Requirements

Assurance Classes

Assurance Families

Assurance Components

Detailed Requirements

Evaluation AssuranceLevels (EAL)

CC - Security Requirements

Functional Requirements

for defining security behavior of the IT product or system:

implemented requirements become security functions

Assurance Requirements

for establishing confidence in Security Functions:

correctness of implementationeffectiveness in satisfying

objectives

CC - Security Functional Classes

Name

AuditCommunicationsCryptographic SupportUser Data ProtectionIdentification & AuthenticationSecurity ManagementPrivacyProtection of TOE Security FunctionsResource UtilizationTOE (Target Of Evaluation) AccessTrusted Path / Channels

Class

FAUFCOFCSFDPFIAFMTFPRFPTFRUFTAFTP

CC - Security Assurance Classes

Name

Configuration ManagementDelivery & OperationDevelopmentGuidance DocumentsLife Cycle SupportTestsVulnerability AssessmentProtection Profile EvaluationSecurity Target EvaluationMaintenance of Assurance

Class

ACMADOADVAGDALCATEAVAAPEASEAMA

CC - Eval. Assurance Levels (EALs)

*TCSEC = “Trusted Computer Security Evaluation Criteria” --”Orange Book”

Name

Functionally TestedStructurally TestedMethodically Tested & CheckedMethodically Designed, Tested & ReviewedSemiformally Designed & TestedSemiformally Verified Design & TestedFormally Verified Design & Tested

EAL

EAL1EAL2EAL3EAL4EAL5EAL6EAL7

*TCSEC

C1C2B1B2B3A1

ITSEC, CC - Summary

• Used primarily for security evaluations and not for generalized IT audits

• Defines evaluation methodology• Based on International Standard (ISO 15408)• Certification scheme in place• Updated & enhanced on a yearly basis• Includes extensible standard sets of security

requirements (Protection Profile libraries)

Comparison of Methods - Criteria

• Standardisation• Independence• Certifiability• Applicability in practice• Adaptability

Comparison of Methods - Criteria

• Extent of Scope• Presentation of Results• Efficiency• Update frequency• Ease of Use

Comparison of Methods - Results

CobiT

3.43.32.72.83.33.11.93.03.12.3

StandardisationIndependenceCertifyabilityApplicability in practiceAdaptabilityExtent of ScopePresentation of ResultsEfficiencyUpdate frequencyEase of Use

BS 7799

3.33.63.33.02.82.92.22.82.42.7

BSI

3.13.53.03.13.32.72.63.03.42.8

ITSEC/CC

3.93.93.72.53.02.61.72.52.82.0

Scores between 1 (low) and 4 (high) - Scores for CobiT, BS7799, BSI from ISACA Swiss chapter; score for ITSEC/CC form H.P. Winiger

CobiT - Assessment

BS 7799 - Assessment

BSI - Assessment

ITSEC/CC - Assessment

Use of Methods for IT Audits

• CobiT: Audit method for all IT processes• ITSEC, CC: Systematic approach for evaluations• BS7799, BSI: List of detailed security measures to

be used as best practice documentation• Detailed audit plans, checklists, tools for technical

audits (operating systems, LANs, etc.)• What is needed in addition:

– Audit concept (general aspects, infrastructure audits, application audits)