CSCE 548 Secure System Standards Risk Management

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CSCE 548 Secure System StandardsRisk Management
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Reading

• This lecture
• McGraw Chapter 2
• Recommended
• Rainbow Series Library, http//www.radium.ncsc.mil
  /tpep/library/rainbow/
• Common Criteria, http//csrc.nist.gov/cc/
• Next lecture
• Software Development Lifecycle Dr. J. Vidal
• Handout on SDLC and UML

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Incident Handling
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How to Response?

• Actions to avoid further loss from intrusion
• Terminate intrusion and protect against
  reoccurrence
• Law enforcement prosecute
• Enhance defensive security
• Reconstructive methods based on
• Time period of intrusion
• Changes made by legitimate users during the
  effected period
• Regular backups, audit trail based detection of
  effected components, semantic based recovery,
  minimal roll-back for recovery.

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Roles and Responsibilities

• User
• Vigilant for unusual behavior
• Report incidents
• Manager
• Awareness training
• Policies and procedures
• System administration
• Install safeguards
• Monitor system
• Respond to incidents, including preservation of
  evidences

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Computer Incident Response Team

• Assist in handling security incidents
• Formal
• Informal
• Incident reporting and dissemination of incident
  information
• Computer Security Officer
• Coordinate computer security efforts
• Others law enforcement coordinator,
  investigative support, media relations, etc.

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Incident Response Process 1.

• Preparation
• Baseline Protection
• Planning and guidance
• Roles and Responsibilities Training
• Incident response team

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Incident Response Process 2.

• Identification and assessment
• Symptoms
• Nature of incident
• Identify perpetrator, origin and extent of attack
• Can be done during attack or after the attack
• Gather evidences
• Key stroke monitoring, honey nets, system logs,
  network traffic, etc.
• Legislations on Monitoring!
• Report on preliminary findings

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Incident Response Process 3.

• Containment
• Reduce the chance of spread of incident
• Determine sensitive data
• Terminate suspicious connections, personnel,
  applications, etc.
• Move critical computing services
• Handle human aspects, e.g., perception
  management, panic, etc.

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Incident Response Process 4.

• Eradication
• Determine and remove cause of incident if
  economically feasible
• Improve defenses, software, hardware, middleware,
  physical security, etc.
• Increase awareness and training
• Perform vulnerability analysis

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Incident Response Process 5.

• Recovery
• Determine course of action
• Reestablish system functionality
• Reporting and notifications
• Documentation of incident handling and evidence
  preservation

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Follow Up Procedures

• Incident evaluation
• Quality of incident (preparation, time to
  response, tools used, evaluation of response,
  etc.)
• Cost of incident (monetary cost, disruption, lost
  data, hardware damage, etc.)
• Preparing report
• Revise policies and procedures

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Security Awareness and Training

• Major weakness users unawareness
• Organizational effort
• Educational effort
• Customer training
• Federal Trade Commission program to educate
  customers about web scams

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Risk Management
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Risk Assessment
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Financial Loss
Dollar Amount Losses by Type
Total Loss (2006) 53,494,290 CSI/FBI Computer
Crime and Security Survey Computer Security
Institute
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Security Protection
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Real Cost of Cyber Attack

• Damage of the target may not reflect the real
  amount of damage
• Services may rely on the attacked service,
  causing a cascading and escalating damage
• Need support for decision makers to
• Evaluate risk and consequences of cyber attacks
• Support methods to prevent, deter, and mitigate
  consequences of attacks

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System Security Engineering (Traditional View)
Specify System Architecture
Identify and Install Safeguards
Identify Threats, Vulnerabilities, Attacks
Prioritize Vulnerabilities
Estimate Risk
Risk is acceptably low
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Risk Management Framework (Business Context)
Understand Business Context
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Understand the Business Context

• Who cares?
• Identify business goals, priorities and
  circumstances, e.g.,
• Increasing revenue
• Meeting service-level agreements
• Reducing development cost
• Generating high return investment
• Identify software risk to consider

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Identify Business and Technical Risks

• Why should business care?
• Business risk
• Direct threat
• Indirect threat
• Consequences
• Financial loss
• Loss of reputation
• Violation of customer or regulatory constraints
• Liability
• Tying technical risks to the business context in
  a meaningful way

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Synthesize and Rank the Risks

• What should be done first?
• Prioritization of identified risks based on
  business goals
• Allocating resources
• Risk metrics
• Risk likelihood
• Risk impact
• Risk severity
• Number of emerging risks

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Define the Risk Mitigation Strategy

• How to mitigate risks?
• Available technology and resources
• Constrained by the business context what can the
  organization afford, integrate, and understand
• Need validation techniques

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Carry Out Fixes and Validate

• Perform actions defined in the previous stage
• Measure completeness against the risk
  mitigation strategy
• Progress against risk
• Remaining risks
• Assurance of mechanisms
• Testing

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Measuring and Reporting

• Continuous and consistent identification and
  storage of risk information over time
• Maintain risk information at all stages of risk
  management
• Establish measurements, e.g.,
• Number of risks, severity of risks, cost of
  mitigation, etc.

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Assets-Threat Model (1)

• Threats compromise assets
• Threats have a probability of occurrence and
  severity of effect
• Assets have values
• Assets are vulnerable to threats

Threats
Assets
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Assets-Threat Model (2)

• Risk expected loss from the threat against an
  asset
• RVPS
• R risk
• V value of asset
• P probability of occurrence of threat
• V vulnerability of the asset to the threat

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System-Failure Model

• Estimate probability of highly undesirable events
• Risk likelihood of undesirable outcome

Threat
Undesirable outcome
System
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Risk Acceptance

• Certification
• How well the system meet the security
  requirements (technical)
• Accreditation
• Managements approval of automated system
  (administrative)

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Building It Secure

• 1960s US Department of Defense (DoD) risk of
  unsecured information systems
• 1970s
• 1977 DoD Computer Security Initiative
• US Government and private concerns
• National Bureau of Standards (NBS now NIST)
• Responsible for standards for acquisition and use
  of federal computing systems
• Federal Information Processing Standards (FIPS
  PUBs)

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NBS

• Two initiatives for security
• Cryptography standards
• 1973 invitation for technical proposals for
  ciphers
• 1977 Data Encryption Standard
• 2001 Advanced Encryption Standard (NIST)
• Development and evaluation processes for secure
  systems
• Conferences and workshops
• Involves researchers, constructors, vendors,
  software developers, and users
• 1979 Mitre Corporation entrusted to produce an
  initial set of criteria to evaluate the security
  of a system handling classified data

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National Computer Security Center

• 1981 National Computer Security Center (NCSC)
  was established within NSA
• To provide technical support and reference for
  government agencies
• To define a set of criteria for the evaluation
  and assessment of security
• To encourage and perform research in the field of
  security
• To develop verification and testing tools
• To increase security awareness in both federal
  and private sector
• 1985 Trusted Computer System Evaluation Criteria
  (TCSEC) Orange Book

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Orange Book

• Orange Book objectives
• Guidance of what security features to build into
  new products
• Provide measurement to evaluate security of
  systems
• Basis for specifying security requirements
• Security features and Assurances
• Trusted Computing Base (TCB) security components
  of the system hardware, software, and firmware
  reference monitor

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Orange Book

• Supply
• Users evaluation metrics to assess the
  reliability of the security system for protection
  of classified or sensitive information when
• Commercial product
• Internally developed system
• Developers/vendors design guide showing security
  features to be included in commercial systems
• Designers guide for the specification of
  security requirements

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Orange book

• Set of criteria and requirements
• Three main categories
• Security policy protection level offered by the
  system
• Accountability of the users and user operations
• Assurance of the reliability of the system

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Security Policy

• Concerns the definition of the policy regulation
  the access of users to information
• Discretionary Access Control
• Mandatory Access Control
• Labels for objects and subjects
• Reuse of objects basic storage elements must be
  cleaned before released to a new user

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Accountability

• Identification/authentication
• Audit
• Trusted path no users are attempting to access
  thr system fraudulently

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Assurance

• Reliable hardware/software/firmware components
  that can be evaluated separately
• Operation reliability
• Development reliability

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Operation reliability

• During system operation
• System architecture TCB isolated from user
  processes, security kernel isolated from
  non-security critical portions of the TCB
• System integrity correct operation (use
  diagnostic software)
• Covert channel analysis
• Trusted facility management separation of duties
• Trusted recovery recover security features after
  TCB failures

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Development reliability

• System reliable during the development process.
  Formal methods.
• System testing security features tested and
  verified
• Design specification and verification correct
  design and implementation wrt security policy.
  TCB formal specifications proved
• Configuration management configuration of the
  system components and its documentation
• Trusted distribution no unauthorized
  modifications

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Documentation

• Defined set of documents
• Minimal set
• Trusted facility manual
• Security features users guide
• Test documentation
• Design documentation
• Personnel info Operators, Users, Developers,
  Maintainers

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Orange Book Levels

• Highest Security
• A1 Verified protection
• B3 Security Domains
• B2 Structured Protection
• B1 Labeled Security Protections
• C2 Controlled Access Protection
• C1 Discretionary Security Protection
• D Minimal Protection
• No Security

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NCSC Rainbow Series

• Orange Trusted Computer System Evaluation
  Criteria
• Yellow Guidance for applying the Orange Book
• Red Trusted Network Interpretation
• Lavender Trusted Database Interpretation

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Evaluation Process

• Preliminary technical review (PTR)
• Preliminary technical report architecture
  potential for target rating
• Vendor assistance phase (VAP)
• Review of the documentation needed for the
  evaluation process, e.g., security features
  users guide, trusted facility manual, design
  documentation, test plan. For B or higher,
  additional documentations are needed, e.g.,
  covert channel analysis, formal model, etc.
• Design analysis phase (DAP)
• Initial product assessment report (IPAR) 100-200
  pages, detailed info about the hardware, software
  architecture, security relevant features, team
  assessments, etc.
• Technical Review Board
• Recommendation to the NCSC

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Evaluation Process

• Formal evaluation phase (FEP)
• Product Bulletin formal and public announcement
• Final Evaluation Report information from IPAR
  and testing results, additional tests, review
  code (B2 and up), formal policy model, proof.
• Recommends rating for the system
• NCSC decides final rating
• Rating maintenance phase (RAMP)
• Minor changes and revisions
• Reevaluated
• Rating maintenance plan

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European Criteria

• German Information Security Agency German Green
  Book (1988)
• British Department of Trade and Industry and
  Ministry of Defense several volumes of criteria
• Canada, Australia, France works on evaluation
  criteria
• 1991 Information Technology Security Evaluation
  Criteria (ITSEC)
• For European community
• Decoupled features from assurance
• Introduced new functionality requirement classes
• Accommodated commercial security requirements

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Common Criteria

• January 1996 Common Criteria
• Joint work with Canada and Europe
• Separates functionality from assurance
• Nine classes of functionality audit,
  communications, user data protection,
  identification and authentication, privacy,
  protection of trusted functions, resource
  utilization, establishing user sessions, and
  trusted path.
• Seven classes of assurance configuration
  management, delivery and operation, development,
  guidance documents, life cycle support, tests,
  and vulnerability assessment.

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Common Criteria

• Evaluation Assurance Levels (EAL)
• EAL1 functionally tested
• EAL2 structurally tested
• EAL3 methodologically tested and checked
• EAL4 methodologically designed, tested and
  reviewed
• EAL5 semi-formally designed and tested
• EAL6 semi-formally verified and tested
• EAL7 formally verified design and tested

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National Information Assurance Partnership (NIAP)

• 1997 National Institute of Standards and
  Technology (NIST), National Security Agency
  (NSA), and Industry
• Aims to improve the efficiency of evaluation
• Transfer methodologies and techniques to private
  sector laboratories
• Functions developing tests, test methods, tools
  for evaluating and improving security products,
  developing protection profiles and associated
  tests, establish formal and international schema
  for CC

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Next Class

• Software Development Lifecycle