ISO/IEC 27005 and Information Security Risk Management: The Key to Corporate Resilience in Turkey

As digitalization accelerates in Turkey, the complexity, frequency, and scope of cyber threats are also increasing. Sectors such as finance, e-commerce, energy, manufacturing, and critical infrastructure are particularly exposed to growing risks, including ransomware, service disruptions, and data breaches. In this context, information security risk management has become not merely a technical requirement but a fundamental element of business continuity, regulatory compliance, and customer trust.

The ISO/IEC 27005 standard provides an internationally recognized framework for the systematic identification, analysis, evaluation, and management of information security risks. This article examines the application of ISO/IEC 27005 within the Turkish context, focusing on its integration with the Personal Data Protection Law (KVKK), critical infrastructure regulations, and sector-specific compliance requirements. It further analyzes how the structured approach of ISO/IEC 27005 contributes to corporate resilience, operational continuity, and competitiveness for Turkish organizations. Through case scenarios and sectoral practices, the study aims to shed light on best practices in information security risk management in Turkey.

Information Security Risk Management in Turkey’s Digitalization Process: The Strategic Role of ISO/IEC 27005

The wave of digital transformation in the 21st century has become a key driver for public institutions, private sector organizations, and critical infrastructures in Turkey. From e-government services to cloud-based platforms, from mobile banking to e-commerce ecosystems, digital solutions are delivering speed and efficiency while simultaneously introducing new security vulnerabilities. Particularly in critical sectors such as financial systems, healthcare, energy grids, and manufacturing facilities, digitalization has made these areas increasingly attractive targets for complex and sophisticated cyber threats.

The Rise of Cyber Threats in Turkey

Recent reports published by TÜBİTAK BİLGEM, the National Cyber Incident Response Center (USOM), and the Information and Communication Technologies Authority (BTK) reveal a continuous increase in ransomware attacks, denial-of-service (DDoS) campaigns, phishing incidents, and data leaks in Turkey. These attacks not only compromise the confidentiality, integrity, and availability of information assets but also directly affect legal liabilities, operational continuity, organizational reputation, and customer trust.

From Technical Measures to Corporate Risk Management

These developments demonstrate that information security can no longer be ensured solely through technical safeguards such as firewalls, antivirus software, or access control systems. In today’s evolving threat landscape, a corporate-level approach is essential—where risks are systematically identified, assessed, prioritized, and continuously managed. At this point, ISO/IEC 27005 emerges as a leading internationally accepted framework, offering a comprehensive methodological roadmap for information security risk management.

The Core Contribution of ISO/IEC 27005 and Its Relevance to Turkey

ISO/IEC 27005 is not a management system standard in itself, but rather a guideline that supports the risk management requirements of ISO/IEC 27001 (particularly clauses 6.1.2 and 6.1.3). Its structured methodology enables organizations to systematically assess their information assets, analyze risks based on likelihood and impact, determine appropriate risk treatment options, and monitor the process in a continuous cycle.

In the Turkish context, the significance of ISO/IEC 27005 can be understood through three key dimensions:

1. Legal and regulatory compliance: The Personal Data Protection Law (KVKK), the Electronic Commerce Law, and critical infrastructure regulations mandate that organizations effectively manage information security risks. ISO/IEC 27005 provides a systematic tool for meeting these obligations.
2. Customer trust and corporate reputation: Data breaches or service disruptions can result not only in financial losses but also in a loss of customer confidence and long-term reputational damage that is difficult to recover.
3. Corporate resilience and sustainability: Being prepared for emerging threats in the digitalization process has become the responsibility of the entire organization, not just security teams. Through its risk-based approach, ISO/IEC 27005 enhances resilience and safeguards operational continuity.

For example, an e-commerce company conducting a risk assessment under ISO/IEC 27005 could identify a critical vulnerability in its customer database in advance and take preventive measures—thereby avoiding both a potential KVKK violation and the erosion of customer trust. Similarly, an energy sector organization could apply the methodology to analyze threats targeting OT/IoT devices and secure production continuity.

Conclusion

In Turkey’s rapidly evolving digital ecosystem, information security risk management is no longer an “option” but one of the fundamental pillars of corporate existence, sustainable growth, and global competitiveness. By offering a compatible, flexible, and practical roadmap, the ISO/IEC 27005 standard responds to this critical need, establishing itself as a strategic guide for organizations on their digital transformation journey.

1. What is ISO/IEC 27005? Core Definition and Related Standards

1.1 Definition and Scope

ISO/IEC 27005 is an internationally recognized guidance standard designed to enable organizations to conduct information security risk management processes in a systematic and sustainable manner. First published in 2008 and periodically updated, the standard was developed specifically to support the risk-based approach of ISO/IEC 27001, the Information Security Management System (ISMS) standard.

ISO/IEC 27005 is not a management system standard but rather a guidance standard, offering organizations methodologies to navigate risk management. Its primary purpose is to ensure that organizations systematically identify risks to their information assets, analyze their likelihood and impact, evaluate them based on results, and define appropriate risk treatment strategies. In addition, monitoring, reviewing, and continuously improving the risk management process lies at the core of ISO/IEC 27005. In this way, information security becomes not a “one-off” project but an integral and dynamic element of the organizational structure.

1.2 Related Standards and Integration

ISO/IEC 27005 is part of the ISO/IEC 27000 family of standards, which provides the global framework for information security management systems. In this context, it is closely related to the following standards:

• ISO/IEC 27001 (ISMS Requirements): The most important related standard to ISO/IEC 27005. ISO 27001 defines the requirements for establishing an ISMS and mandates a risk-based approach. ISO/IEC 27005 provides the methodologies for meeting especially Clause 6.1.2 (Information Security Risk Assessment) and Clause 6.1.3 (Information Security Risk Treatment). Therefore, ISO/IEC 27005 is a critical complement for the effective implementation of ISO 27001.
• ISO/IEC 27002 (Control Set): While ISO 27005 defines the methodology for identifying and assessing risks, ISO/IEC 27002 specifies the technical and administrative controls to mitigate those risks. For instance, a high-impact, high-likelihood risk may be addressed through access control or encryption measures recommended in ISO 27002.
• ISO/IEC 31000 (Enterprise Risk Management): While ISO 27005 is specific to information security, ISO 31000 sets out the general principles of enterprise risk management. In Turkey, many organizations increasingly need to integrate information security risk management into their overall ERM processes, and ISO/IEC 27005 directly contributes to this integration.
• Other Related Standards: ISO/IEC 22301 (Business Continuity Management), IEC 62443 (Security in Industrial Automation and Control Systems), and NIST CSF (Cybersecurity Framework by the U.S. National Institute of Standards and Technology) can also be applied in conjunction. Particularly for critical infrastructures in Turkey (energy, transportation, finance), such cross-standard integrations are becoming increasingly important.

1.3 The Importance of ISO/IEC 27005 in the Turkish Context

In Turkey, information security risk management is not merely a technical issue but is directly linked to regulatory compliance, reputation management, and customer trust. Several factors amplify the importance of ISO/IEC 27005:

• KVKK (Personal Data Protection Law): Processing and protecting personal data in Turkey is a legal obligation that can result in severe administrative fines and reputational losses. ISO/IEC 27005’s risk assessment methodology ensures that data security risks are systematically addressed in KVKK compliance projects.
• BTK and USOM Regulations: The Information and Communication Technologies Authority (BTK) and the National Cyber Incident Response Center (USOM) require especially critical infrastructure operators to monitor and report cybersecurity risks. ISO/IEC 27005 provides a practical tool for meeting these requirements.
• Sectoral Dynamics: In sectors such as finance, energy, healthcare, and e-commerce, customer trust, regulatory compliance, and operational continuity are critical. This makes it essential for risk management to be based on a structured framework.
• Corporate Resilience: Turkey’s cyber threat landscape includes targeted attacks from both national and international actors. ISO/IEC 27005 enhances institutional cyber resilience by anticipating, mitigating, and managing these risks.

1.4 Purpose and Contributions of ISO/IEC 27005

In summary, the primary objectives of ISO/IEC 27005 are:

• To ensure the systematic identification of information security risks.
• To guide the analysis and prioritization of risks based on likelihood and impact.
• To support the determination and implementation of appropriate risk treatment options (mitigation, acceptance, transfer, or avoidance).
• To provide a methodological framework for monitoring, reviewing, and continuously improving the risk management process.

Thus, ISO/IEC 27005 not only helps organizations meet regulatory obligations but also strengthens customer trust, ensures operational continuity, and provides strategic resilience in digital transformation journeys.

Key Takeaways:

• Definition: ISO/IEC 27005 is an international standard that provides guiding principles and methodologies for planning, implementing, monitoring, reviewing, and improving an organization’s information security risk management processes. It is a guidance standard, not a management system standard.
• Relationship: ISO/IEC 27005 lies at the core of the ISMS standard ISO/IEC 27001. It is one of the primary methodologies for fulfilling the requirements of “Risk Assessment and Risk Treatment” (Clauses 6.1.2 and 6.1.3).
• Purpose: To help organizations:
• Systematically identify information security risks.
• Analyze and evaluate risks based on likelihood and impact.
• Define appropriate risk treatment options (mitigation, acceptance, transfer, avoidance) to achieve an acceptable level of risk.
• Continuously monitor and improve the risk management process.
• Turkish Context: KVKK compliance, critical infrastructure protection regulations, and rising customer expectations make ISO/IEC 27005’s structured risk approach indispensable for Turkish organizations.
• Example: An e-commerce company, through risk assessment under ISO 27005, may identify a vulnerability in its customer database in advance, strengthen its defenses, and thus prevent both a potential data breach and a KVKK penalty.

2. The ISO/IEC 27005 Approach to Information Security Risk Management

The ISO/IEC 27005 standard addresses information security risk management as a continuous, cyclical, and strategy-integrated process. The standard does not mandate a single methodology; instead, it offers a flexible framework that can be adapted to different sectors, organizational sizes, and maturity levels. This flexibility is a significant advantage, particularly when considering the diverse structures and regulatory compliance requirements of institutions in Turkey.

2.1 Establishing the Risk Management Framework (Context Definition)

The first step of ISO/IEC 27005 is to clearly define the organization’s context. At this stage:

• Defining Scope: The information assets, processes, and systems to be included within the scope of risk management are clarified. For example, in a Turkish bank, the customer CRM platform, mobile banking applications, and SWIFT infrastructure may fall within the scope.
• Defining Risk Criteria: Acceptable risk levels are established. These criteria may be based on parameters such as financial loss, legal sanctions (KVKK, BRSA regulations), customer trust, or operational continuity.
• Selecting Methodology: The organization determines whether to apply a qualitative, quantitative, or hybrid approach. In Turkey, SMEs typically favor qualitative methods, while larger banks and telecommunications firms often employ quantitative models for more sophisticated risk analysis.
• Assessing Internal and External Context: Internal policies, business processes, and organizational culture are considered, along with external factors such as legal regulations (KVKK, E-Commerce Law, critical infrastructure regulations) and the international threat landscape.

2.2 Risk Assessment

This stage lies at the heart of risk management and consists of three sub-steps:

1. Risk Identification: Potential threats to the organization’s information assets (cyberattacks, natural disasters, human errors, supplier risks) are identified. In Turkey, ransomware, DDoS attacks, and social engineering attempts are particularly prominent.
2. Risk Analysis: The likelihood and potential impact of threats exploiting identified vulnerabilities are evaluated. For instance, an attack on SCADA systems in an energy company would be classified as having a “very high” impact.
3. Risk Evaluation (Prioritization): Findings are typically plotted into a risk matrix using the probability × impact formula, which helps determine which risks require immediate action.

2.3 Risk Treatment

ISO/IEC 27005 defines risk treatment through the following options:

• Mitigation: Reducing risk to an acceptable level through security controls and policies (e.g., multi-factor authentication).
• Avoidance: Eliminating high-risk activities or altering processes (e.g., storing sensitive data on local servers instead of the cloud).
• Transfer: Shifting the risk through insurance or outsourcing to third-party providers.
• Acceptance: Having senior management formally approve the remaining risk within pre-defined criteria.

In the Turkish context, obtaining explicit, documented approval from senior management for residual risks is often overlooked, making it a critical step to integrate into corporate governance.

2.4 Risk Monitoring and Review

According to ISO/IEC 27005, risk management is not a “one-time project” but a dynamic process. Changes in the threat landscape, new regulations, technological transformations, and organizational growth continuously alter the risk profile. Therefore:

• Risks must be periodically reviewed,
• The effectiveness of risk treatment plans must be measured,
• Emerging vulnerabilities or threats (e.g., AI-based attacks) must be integrated into the system on an ongoing basis.

2.5 Risk Communication and Stakeholder Engagement

Risk management is not solely the responsibility of information security teams. ISO/IEC 27005 emphasizes effective communication of risks with all relevant stakeholders, including management, employees, business partners, and even customers. In Turkey, executive sponsorship and embedding risk awareness into corporate culture are critical success factors.

3. Core Principles of ISO/IEC 27005 — Practical Application in Turkey

1) Organization-specific Contextualization

• Meaning: Each organization has unique assets, threats, business processes, legal obligations, and risk appetite. ISO 27005 does not provide a “one-size-fits-all” solution; it serves as guidance.
• Implementation: Detailed context definition (scope) — document critical assets, business processes, stakeholders, legal requirements, and operational boundaries. Clarify which data categories are processed under KVKK (sensitive/personal data).
• Turkey-specific Consideration: Map the impact of regulations (KVKK, sectoral regulatory rules) clearly, as priorities vary across banking, healthcare, and energy sectors.
• Metrics / KPIs: Scope coverage in the risk inventory (%), identification rate of critical assets.
• Common Mistake: Directly applying generic templates with “done because the standard requires it” approach, leading to incorrect scope and missing asset definitions.

2) Value-focused / Asset-centric Approach

• Meaning: Evaluate risks based on asset value and impact on business processes. Every control investment should be proportional to the value of the protected asset.
• Implementation: Asset classification (weighting confidentiality, integrity, availability), categorize financial/operational/reputation/application impact, establish a data classification policy.
• Turkey-specific Consideration: Legal and reputational impacts under KVKK can be significant independent of financial losses; consider the effect of personal data breaches on fines and reputation.
• KPIs: Percentage of classified assets in inventory, number of controls assigned to high-value assets.
• Common Mistake: Applying the same level of control to every asset (resource waste).

3) Continual Process / PDCA

• Meaning: Risk management is not a one-off project; it should be continuously updated within a plan-do-check-act (PDCA) cycle.
• Implementation: Periodic risk assessments (at least annually, plus interim assessments triggered by changes), integration with change management, automated alerts (GRC/SIEM) for re-assessment after triggering events.
• Turkey-specific Consideration: Be prepared for regulatory audits, audit periods, and supplier contracts requiring periodic reporting.
• KPIs: Compliance with risk assessment schedules, time to update risk after changes (similar to MTTR).
• Common Mistake: Treating ISO 27001 certification as a one-time checkbox.

4) Defined Risk Criteria & Appetite

• Meaning: Clearly define probability/impact thresholds, acceptable risk levels, and management approval processes.
• Implementation: Organization-wide risk appetite documentation; define acceptable levels for different risk types (financial thresholds, operational downtime, reputation metrics). Obtain executive approval and conduct regular revisions.
• Turkey-specific Consideration: Board/executive approval processes must be formalized; low tolerance may be needed for KVKK and regulatory risks.
• KPIs: Percentage of risks approved by management; number of accepted residual risks.
• Common Mistake: Risk acceptance decisions are unsigned or undocumented.

5) Stakeholder Engagement & Governance

• Meaning: Effective risk management requires active participation from IT, legal, HR, business units, and senior management.
• Implementation: Assign risk ownership, RACI matrices, regular management reporting, risk committee or board-level risk panels.
• Turkey-specific Consideration: Include legal/compliance units in corporate decision-making to incorporate KVKK and sectoral regulation perspectives.
• KPIs: Risk ownership assignment rate, number of regular management reviews.
• Common Mistake: Leaving risk management solely to IT.

6) Threat-informed & Vulnerability-driven

• Meaning: Risk assessment should be informed by current threats and vulnerabilities; prioritize based on intelligence.
• Implementation: Monitor USOM/TÜBİTAK and global sources, implement vulnerability scanning programs, patch management SLAs, integrate threat feeds (prioritize intelligence for critical assets).
• Turkey-specific Consideration: Integrate local CERT/USOM alerts and sectoral threat reports; evaluate local supplier vulnerabilities.
• KPIs: Mean time to remediate vulnerabilities (MTTR), number of exploitable vulnerabilities.
• Common Mistake: Conducting vulnerability scans but not integrating results into risk assessment.

7) Methodology Fit: Qualitative, Quantitative, or Hybrid

• Meaning: ISO 27005 does not mandate a methodology; choose qualitative, quantitative, or hybrid methods based on organizational needs.
• Implementation:
• SMEs / startups: Qualitative (e.g., 1–5 scale), short and easy to apply.
• Large organizations / financial institutions: Quantitative (expected financial loss, frequency models) or hybrid.
• Hybrid: Quantitative for critical assets, qualitative for the rest.
• Turkey-specific Consideration: Quantitative approaches are common in financial and regulated sectors; SMEs prefer practical, lightweight solutions.
• Example Scale: Probability 1–5, Impact 1–5; Risk = P × I, results 1–25 color-coded.
• KPIs: Proportion of critical risks assessed with quantitative metrics.
• Common Mistake: Overly complex methodology or, conversely, random scores without methodological basis.

8) Risk Treatment — Cost-effectiveness and Prioritization

• Meaning: Risk treatment options (mitigation, acceptance, transfer, avoidance) should be selected based on business needs and available resources; cost-effectiveness analysis is required.
• Implementation: Conduct cost-benefit analysis for each recommendation, obtain business unit approval, prepare implementation plan, define KPIs. Consider cyber insurance, risk transfer via supplier contracts.
• Turkey-specific Consideration: The cyber insurance market is growing; however, contract-based transfers (SLA, SSO) and supplier audits are critical. Administrative/fine risks under KVKK are not fully covered by insurance — management approval is essential.
• KPIs: Completion rate of risk mitigation plans, ROI per risk (cumulative).
• Common Mistake: Choosing to “mitigate” all risks — leads to resource inefficiency.

9) Residual Risk Documentation and Management Approval

• Meaning: Residual risks remaining after treatment must be formally accepted by management and recorded.
• Implementation: Maintain a residual risk register, obtain approval signatures, establish periodic review cycles, ensure residual risks are visible in management panels.
• Turkey-specific Consideration: Risks cannot be considered “accepted” without management approval; maintain evidence for regulatory purposes.
• KPIs: Percentage of residual risks not approved.
• Common Mistake: Keeping residual risks undocumented under “silent acceptance.”

10) Monitoring, Measurement, Reporting, and Assurance

• Meaning: The effectiveness of controls must be measured; KPIs/KRIs defined; internal audits and independent checks performed.
• Implementation: Use SIEM, log management, control effectiveness testing, periodic penetration tests, management reporting. Secure processes via internal/external audit programs.
• Turkey-specific Consideration: Maintain measurable evidence for audits and regulatory reporting.
• Example KPIs/KRIs: Number of critical security events detected per year, mean time to detect (MTTD), mean time to respond (MTTR), control effectiveness rate.
• Common Mistake: KPIs are not operationally relevant, serving as “useless” indicators.

11) Third-party and Supply Chain Risk Management

• Meaning: Supplier risks should be assessed to ensure the security of provided services.
• Implementation: Supplier classification, due diligence, contractual security requirements, periodic audits, third-party SLAs. Access controls and transparency requirements for critical suppliers.
• Turkey-specific Consideration: Compliance levels vary among local suppliers; security requirements must be explicitly stated in contracts.
• KPIs: Percentage of critical suppliers assessed, number of supplier-related security incidents.
• Common Mistake: Considering supplier risk only after signing contracts.

12) Communication, Awareness, and Culture

• Meaning: Risk awareness must be embedded in organizational culture; clear rules for routine updates and incident communication are needed.
• Implementation: Role-based awareness programs, regular tabletop exercises, incident communication plans (internal/external stakeholders, regulatory notifications — considering KVKK breach reporting requirements).
• KPIs: Training participation rate, social engineering/spear-phishing test success rate.
• Common Mistake: Treating awareness activities as “just a presentation.”

13) Legal Compliance and Regulatory Mapping

• Meaning: Risk management should align with legal obligations; integrate KVKK, sectoral regulations, and contractual obligations into risk assessment.
• Implementation: Regulatory-cost-impact mapping, data processing inventory, DPIA (Data Protection Impact Assessment) processes, breach notification procedures.
• Turkey-specific Consideration: Consider KVKK notification deadlines and sanction risks in case of breaches.
• KPIs: Number of compliance checks, time to close identified non-compliance issues.
• Common Mistake: Treating legal compliance solely as a legal department issue.

14) Business Continuity and Resilience

• Meaning: Information security risk management must be integrated with business continuity plans (BCP/DR). Strong security not only prevents attacks but ensures rapid recovery.
• Implementation: Link critical service RTO/RPO values with risk assessment results; feed BCP scenarios from risk data.
• KPIs: Frequency and success rate of BCP tests, RTO compliance rate for critical services.
• Common Mistake: Preparing BCP plans detached from technical security controls.

15) Measurability, Evidence, and Auditability

• Meaning: Decisions and actions must be auditable and evidence-based — no black-box approach.
• Implementation: Maintain risk assessment records, management approvals, implementation evidence, test logs, and reports. Transparent documentation for ISO 27001 audits.
• KPIs: Rate of closing audit findings, number of missing documents.
• Common Mistake: Relying on verbal statements; lack of written evidence.

16) Scalability & Pragmatism

• Meaning: Methods should be scalable according to organization size and resources; overly complex methodologies are not feasible for smaller organizations.
• Implementation: Modular risk management programs; distinction between core (must-have) and advanced (nice-to-have) processes. “Lite” risk guides for SMEs.
• Turkey-specific Consideration: Do not ignore digital supply chain risks shared by SMEs; evaluate scalable practical solutions (managed services).
• KPI: Program implementation speed, cost/impact ratio.
• Common Mistake: Trying to integrate standards directly into a small organization.

17) Tools & Automation Support

• Meaning: GRC solutions, SIEM, vulnerability scanners, asset management, and workflow automation accelerate the risk process and improve traceability.
• Implementation: Automated risk register, trigger-based reassessments, control performance dashboards, integrations (CMDB ↔ GRC ↔ SIEM).
• Turkey-specific Consideration: Consider local regulations/data location issues when selecting technology. For cloud providers, verify KVKK compliance and data processing conditions.
• KPI: Percentage of risk records updated automatically, reduction in manual operations.
• Common Mistake: Focusing on tools first without properly setting up processes for automation.

18) Measurement Tools: Example Risk Matrix, Risk Register Columns, and KPIs

• Risk Matrix Scale Suggestion: Probability (1–5), Impact (1–5) → Risk = P x I (1–25)
• 1–5: Low / Green
• 6–10: Medium / Yellow
• 11–15: High / Orange
• 16–25: Critical / Red
• Risk Register – Example Columns: Risk ID | Date | Asset | Threat | Vulnerability | Existing Controls | Probability (P) | Impact (I) | Risk Score (R) | Recommended Action | Owner | Completion Date | Residual Risk Score | Management Approval (name/date) | Notes.
• Key KPI Examples: MTTD, MTTR, time to remediate critical vulnerabilities, reduction rate in high/critical risks, training participation rate, supplier security compliance rate.

19) Common Pitfalls & Recommended Corrective Actions

• Pitfall: Viewing risk management as only a “documentation” activity.
• Remedy: Link processes to operational KPIs.
• Pitfall: Lack of management commitment.
• Remedy: Prepare short, impact-focused reports for senior management; present critical residual risks directly.
• Pitfall: Ignoring supplier risks.
• Remedy: Include critical supplier classification and mandatory controls.
• Pitfall: Relying solely on technical controls.
• Remedy: Invest in a balanced approach across people, process, and technology.

20) Practical Tips & Good Practice Examples

• First 90 days: Inventory critical assets, define risk criteria with senior management approval, identify 10–15 critical risks, and create short-term mitigation plans.
• 6-month target: Automate risk register, generate monthly management summaries, initiate supplier audits.
• Annual: Conduct comprehensive tabletop exercises, penetration tests, and management reviews.
• Sector-specific integration:
• Finance → more frequent quantitative models;
• Manufacturing/OT → analysis weighted toward physical/operational impacts;
• Healthcare → KVKK compliance + patient safety integration.

ISO/IEC 27005 as a Strategic Tool

ISO/IEC 27005 approaches the information security risk management framework not merely as a technical obligation, but as a strategic tool that enhances organizational resilience and ensures sustainable business continuity. The standard is built on certain fundamental principles, which must be applied considering the unique needs, legal regulations, and sector-specific dynamics of businesses in Turkey.

Organization-specificity

Continuity and Cyclicality

Stakeholder Engagement

Threat Intelligence and Vulnerability Management

Value-based Approach

Conclusion

4. How to Conduct Risk Assessment According to ISO 27005

The ISO/IEC 27005 standard does not impose a single methodology for managing information security risks; rather, it guides organizations to develop a structured approach tailored to their context and risk profile. In practice in Turkey, especially considering KVKK, sector-specific regulations, and critical infrastructure requirements, the risk assessment process should cover both technical and managerial dimensions. Below is a detailed description of the risk assessment steps recommended by ISO 27005:

1. Creating an Asset Inventory

Turkey Practice Examples:

• All systems, databases, and file storage mechanisms processing personal data under KVKK are inventoried.
• In the financial sector, customer credit and KYC data, payment systems, and financial reporting processes are defined as critical assets.
• In the manufacturing sector, R&D data, production process data, and IoT/OT device data are considered critical assets.

At this stage, the CPATürk approach prioritizes resources toward the most critical assets according to the organization’s sector-specific risk profile.

2. Threat Identification

Turkey Examples and Data Sources:

• TÜBİTAK BİLGEM and BTK reports indicate an increase in ransomware and DDoS attacks.
• In the financial sector, targeted cyber attacks and phishing attempts are highly probable threats.
• In e-commerce companies, POS systems, payment gateways, and customer data are the most frequently targeted areas.

Documenting threats as a contextualized and prioritized list is critical for the accuracy of subsequent analysis steps.

3. Vulnerability Assessment

Example Vulnerabilities:

• Outdated software, weak passwords, missing security patches.
• Physical security gaps (unauthorized access to server rooms).
• Human factor risks: untrained personnel, employees susceptible to social engineering attacks.
• Misconfigured access controls or data sharing permissions in cloud environments.

Considering KVKK and critical infrastructure regulations in Turkey, vulnerabilities should be analyzed from both technical and regulatory perspectives.

4. Existing Controls Assessment

Turkey Practice Examples:

• Data protection and access management controls are reviewed in line with KVKK and ISO 27001 Annex A controls.
• In manufacturing and OT/IoT environments, IEC 62443 standards and network segmentation controls are reviewed.
• Whether risks are under control is assessed using an effectiveness scale (Insufficient / Partially Adequate / Adequate).

5. Likelihood Assessment (P)

Turkey Example:

• In the financial sector, the likelihood of targeted attacks and phishing attempts may be rated high.
• In small-scale SMEs, ransomware risks may be rated medium due to limited technical controls.

6. Impact Assessment (I)

Turkey Examples:

• Leakage of customer KYC data: Very high impact → KVKK fines + loss of customer trust.
• OT device attack on a production line: High impact → production downtime, supply chain disruption, industrial espionage.
• Unauthorized data sharing in cloud environments: Medium–high impact → exposure of trade secrets, contract violations.

Multi-dimensional criteria can be used for impact assessment: financial, operational, reputational, regulatory/compliance, and strategic impacts.

7. Calculating Risk Level (R)

Turkey Practice Examples:

• Financial sector: customer data leak → Very high risk (P: 4, I: 5 → R: 20 / Very High).
• SME: website outage → Medium risk (P: 3, I: 3 → R: 9 / Medium).

This matrix supports management in making prioritized decisions.

8. Risk Prioritization

Turkey Practice and Practical Recommendations:

• Under KVKK and critical infrastructure considerations, personal data leaks and service outage risks are always prioritized.
• Cost-effectiveness, feasibility, and acceptability of residual risk should be evaluated during prioritization.
• Reporting risks to the board and obtaining approval is a critical step often overlooked in Turkey.

5. Practical Examples of ISO/IEC 27005 Implementation

Example 1: Payment System Security in the Retail Sector

• Risk: Skimming/cyber attack risk targeting POS systems, leakage of customer credit card data.
• ISO 27005 Application: Risk assessment integrated with PCI DSS requirements. POS terminals, network security, data encryption, and third-party service provider risks were analyzed.
• Treatment: Implementation of P2PE (Point-to-Point Encryption), frequent security audits, and PCI DSS training for personnel.
• Result: PCI DSS compliance achieved, significant reduction in data breach risk, increased customer trust.
• CPATürk Contribution: Consulting for PCI DSS and ISO 27001/27005 integration, independent security testing.

Example 2: Data Loss Prevention (DLP) after Cloud Migration

• Risk: Unauthorized sharing or leakage of sensitive customer and supplier contracts during or after migration to the cloud.
• ISO 27005 Application: Risk analysis based on cloud service models (IaaS, PaaS, SaaS), data classification, user access rights, and data flows. KVKK and contractual confidentiality obligations were considered.
• Treatment: Sensitive data labeling and classification policies, DLP rules enforced through Cloud Access Security Broker (CASB), user awareness training.
• Result: Prevention of unauthorized sharing of sensitive data, minimized risk of KVKK violations and trade secret loss.
• CPATürk Contribution: Risk assessment of cloud security architecture, support in creating and implementing DLP policies.

Example 3: OT/IoT Security and Industrial Espionage Risk in Manufacturing

• Risk: Cyber attacks on OT (Operational Technology) devices and IoT sensors in production lines (sabotage, data theft—especially R&D data).
• ISO 27005 Application: Inventory of OT/IoT devices, analysis of physical and logical access points, device vulnerabilities, and data flows. Industrial espionage scenarios evaluated.
• Treatment: Segmentation of OT and IT networks, dedicated OT security solutions, hardening device security configurations, enhanced physical security measures.
• Result: Protection of production continuity, safeguarding critical industrial data (product designs, process knowledge) that provides competitive advantage.
• CPATürk Contribution: OT/IoT security risk assessment and consulting integrated with IEC 62443 standards.

ISO/IEC 27005:2022 provides a comprehensive guide for information security risk management. The following examples illustrate how this standard is applied in various sectors in Turkey with concrete, detailed scenarios:

Healthcare Sector Implementation: Hospital Information Systems

Scenario:

ISO/IEC 27005 Application:

1. Risk Identification: Threats such as unauthorized access to patient data, data loss, or cyberattacks on the system are identified.
2. Risk Analysis: The likelihood and potential impact of these threats are evaluated. For example, a ransomware attack could make patient data inaccessible.
3. Risk Assessment: Risks are prioritized based on likelihood and impact levels.
4. Risk Treatment: Measures such as firewalls, encryption techniques, and regular backup strategies are implemented.
5. Monitoring and Review: The system is continuously monitored, and vulnerabilities are addressed promptly when identified.

This process enhances the effectiveness of the hospital’s Information Security Management System (ISMS) and ensures the protection of patient data.

Financial Sector Implementation: Banking Information Systems

Scenario:

ISO/IEC 27005 Application:

1. Risk Identification: Potential threats include cyberattacks on systems, internal threats, and data leaks.
2. Risk Analysis: The likelihood and possible impact of these threats are assessed. For example, the likelihood of a DDoS attack disrupting banking services is analyzed.
3. Risk Assessment: Risks are prioritized based on likelihood and impact levels.
4. Risk Treatment: Measures such as firewalls, multi-factor authentication, and anomaly detection are implemented.
5. Monitoring and Review: The system is regularly monitored, and vulnerabilities are addressed promptly when detected.

This process increases the effectiveness of the bank’s ISMS and ensures the protection of customer data.

Public Sector Implementation: Municipal Digital Services

Scenario:

ISO/IEC 27005 Application:

1. Risk Identification: Potential threats such as cyberattacks, data leaks, and system failures are identified.
2. Risk Analysis: The likelihood and potential impact of these threats are evaluated. For example, a data leak could result in the exposure of citizens’ personal information.
3. Risk Assessment: Risks are prioritized based on likelihood and impact levels.
4. Risk Treatment: Measures such as data encryption, access control, and regular system updates are implemented.
5. Monitoring and Review: The system is continuously monitored, and security vulnerabilities are addressed promptly.

This process enhances the municipality’s ISMS and ensures citizens can access digital services securely.

Industrial Sector Implementation: Manufacturing Facility Automation Systems

Scenario:

ISO/IEC 27005 Application:

1. Risk Identification: Potential threats include cyberattacks, internal threats, and technical failures.
2. Risk Analysis: The likelihood and potential impact of these threats are evaluated. For example, a cyberattack could stop the production line.
3. Risk Assessment: Risks are prioritized based on likelihood and impact levels.
4. Risk Treatment: Measures such as network segmentation, firewalls, and intrusion detection are implemented.
5. Monitoring and Review: The system is regularly monitored, and vulnerabilities are addressed promptly.

This process increases the effectiveness of the facility’s ISMS and ensures the security of production processes.

Training and Awareness Programs

To implement ISO/IEC 27005 effectively, employees must be educated on information security. Training and awareness programs help employees recognize potential threats and take appropriate security measures.

Continuous Improvement and Monitoring

ISO/IEC 27005 emphasizes that information security risk management is a continuous process. Therefore, risks should be regularly monitored, and risk assessment processes should be updated as new threats emerge. This approach allows organizations to continuously improve their information security management systems.

Conclusion: ISO/IEC 27005 – The Key to Corporate Resilience

ISO/IEC 27005 provides a robust framework that allows you to manage information security risks scientifically and systematically, rather than leaving them to chance. It is not only about protecting against cyber threats but also a critical strategic investment to build customer trust, ensure regulatory compliance, safeguard reputation, and guarantee operational continuity. In Turkey’s dynamic and sometimes challenging digital environment, effectively implementing ISO 27005 is essential for achieving sustainable success and resilience in your organization’s digital transformation journey.

In today’s increasingly digital Turkey, the security of information assets has become a critical factor for competitiveness and operational sustainability, whether in the public or private sector. The constantly evolving nature of cyber threats, the growing visibility of internal threats, and regulatory obligations (KVKK, critical infrastructure regulations, sector-specific standards) compel organizations to adopt a proactive and systematic risk management approach. ISO/IEC 27005 provides an internationally recognized framework that addresses this need.

The Turkey-specific examples presented throughout this article clearly demonstrate the applicability and flexibility of ISO/IEC 27005 across different sectors. From protecting patient data in the healthcare sector, safeguarding customer and transaction data in finance, securing OT/IoT systems in manufacturing, to preserving personal data in public institutions and educational organizations, the methods offered by this standard enable organizations to systematically identify, analyze, and take effective measures against threats. Notably, the stages of risk assessment, risk treatment, monitoring, and continuous improvement allow organizations not only to detect risks but also to optimize risk tolerance and strategically manage resources.

In the Turkish context, integrating KVKK and sector-based regulations with international standards further amplifies the importance of ISO/IEC 27005. Organizations gain tangible benefits beyond legal compliance, including reputation management, customer trust, and operational continuity. Particularly, when risk communication and stakeholder involvement are combined with top management support and employee awareness, it fosters a pervasive information security culture across the organization.

In summary, implementing ISO/IEC 27005 provides a scientific and structured approach to ensure information security risks are not left to chance. This process enables organizations to gain resilience against cyber threats and secure a sustainable competitive advantage in their digital transformation journey. In Turkey’s dynamic business environment, organizations that effectively integrate corporate risk management with ISO/IEC 27005 ensure both regulatory and operational compliance while placing information security at the core of strategic decision-making.

In short, ISO/IEC 27005 is not merely a standard or guide; it is a critical strategic tool that strengthens corporate resilience, enhances customer trust, and supports sustainable success for organizations in Turkey. In this context, an effective risk management approach is an essential prerequisite for modern organizations on their information security journey.

At CPATürk, we are with you on this journey. To learn more about our consulting, training, or audit services for ISO/IEC 27005 and information security risk management, visit our website or contact our expert team. Let’s build your corporate digital resilience together.

References:

• ISO/IEC 27005:2022. (2022). Information security, cybersecurity and privacy protection — Guidance on managing information security risks. International Organization for Standardization. ISO
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