Application Security with ISO 27001

5 mins read

Understanding application security controls is vital to ensure the security and integrity of applications, protecting your organization and clients from potential breaches


In today's fast-paced digital landscape, where technology continuously reshapes how businesses operate, safeguarding the security of our applications has never been more imperative. To bolster our security measures, ISO 27001 provides comprehensive controls to safeguard our most valuable assets. This article delves deeply into ISO 27001 controls related to application security, addressing both software development companies seeking to create secure applications within the ISO 27001 framework and third-party users striving for ISO 27001 compliance. Our goal is to illuminate the indispensable steps these organizations must undertake to fortify their applications and shield sensitive data from potential threats.

Understanding ISO 27001

ISO 27001, renowned worldwide, furnishes a systematic approach to managing and safeguarding sensitive information. Its framework encompasses a diverse spectrum of controls and protective measures, all meticulously devised to mitigate risks, uphold data confidentiality, preserve data integrity, and fortify the accessibility of mission-critical information. In this article, we will emphasize the technological controls within ISO 27001, particularly those designed to augment application security.

Whether you are a software development company focused on constructing secure applications aligned with the ISO 27001 framework or a third-party user dedicated to achieving ISO 27001 compliance and seeking insights into your vendor's application security practices, this document is your invaluable resource. Understanding application security controls is vital to ensure the security and integrity of applications, protecting your organization and clients from potential breaches and vulnerabilities.

1. Access to Source Code (ISO 27001: 8.4)

A cornerstone of application security lies in managing access to source code, development tools, and software libraries. Prudent control over who can access and modify source code is essential to prevent unauthorized alterations or the accidental introduction of vulnerabilities during development. Robust access controls significantly reduce the risk of security breaches and uphold the sanctity of your applications. Some of the basic industry best practices include:

Version Control Systems (VCS): A VCS records and tracks the history of code files, facilitating version comparisons and merges. Git, Subversion, and Mercurial are popular VCS options.

Code Repositories: Code repositories store code files and versions with public or private access options. GitHub, Bitbucket, and GitLab are commonly used repository platforms.

Code Access Levels: Permissions assigned to users or user groups within code repositories determine their actions, such as reading, writing, executing, or deleting. These levels vary based on the VCS and platform, including read-only, write, admin, and owner access.

Code Access Policies: These rules and guidelines ensure code and repository security, reducing unauthorized access, data breaches, code conflicts, and errors. Strong passwords, limited access, regular reviews, branch/tag usage, pull requests, code reviews, hooks, and tests contribute to code security.

Code Access Tools: Software tools like command-line interfaces (CLI), graphical user interfaces (GUI), and integrated development environments (IDE) aid in interacting with version control systems and repositories, simplifying tasks such as code editing, committing, pushing, pulling, merging, and comparing.

2. Management of Technical Vulnerabilities (ISO 27001: 8.8)

Maintaining vigilance regarding technical vulnerabilities in your information systems is paramount. This control necessitates ongoing monitoring and an in-depth understanding of your organization's vulnerability landscape. Timely identifying and remedying these weaknesses shield your applications against potential exploitation and emerging cyber threats.

The organization must establish clear roles and responsibilities for technical vulnerability management, encompassing tasks like vulnerability monitoring, risk assessment, asset patching, tracking, and coordination.

Additionally, resources for identifying and staying informed about relevant technical vulnerabilities based on asset inventory changes should be regularly updated. A defined timeline for responding to potential vulnerabilities is crucial.

When potential weaknesses are identified, the organization must acknowledge associated risks and take appropriate actions, including patching compromised systems or implementing other controls. These actions should align with change management protocols or incident response procedures, depending on the severity of the issue.

Assessing the risk of installing a patch and comparing it to the risks posed by the vulnerability is essential before patch deployment. Furthermore, patches must be thoroughly checked and reviewed to ensure safety and prevent adverse side effects. Various tests, such as turning off vulnerable services and enhancing network access controls, may be necessary.

Maintaining an audit log for all undertaken procedures is imperative. Regular monitoring and assessment of the technical vulnerability management process ensure its efficiency and effectiveness, prioritizing high-risk systems.

Effective coordination between incident and technical vulnerability management processes is essential to relay vulnerability information to the incident response mechanism.

Lastly, the organization should establish procedures for identifying vulnerabilities without suitable countermeasures. In such cases, risk assessment and the definition of detective and corrective measures are vital steps.

3. Secure Development Life Cycle (ISO 27001: 8.25)

Establishing and adhering to secure software and system development practices is fundamental. A secure development life cycle (SDLC) ensures that security considerations are ingrained from the outset, minimizing the risk of vulnerabilities in your applications. A structured development approach that places security at its core yields robust and resilient software solutions.

The SDLC is composed of people, processes, and technology components. It encompasses phases that align with different development methodologies such as waterfall, agile, and DevOps. The SDLC phases include requirements, design, implementation, testing, and release/response.

In the requirements phase, security best practices are integrated into product functionality, specifying what the product must, may, or should do from a security perspective. In agile, these requirements are expressed as user stories.

The design phase involves secure architectural planning and threat modeling to identify and mitigate potential attacks before coding begins.
Implementation focuses on writing secure code and includes standards and automated tools like static and dynamic application security testing (SAST and DAST).

The testing phase incorporates security functional test plans, vulnerability scanning, and penetration testing to assess the product's security.

The final phase encompasses release and response. Release occurs after confirming all security activities against the final build, while response deals with external reporting of security issues.

Additional SDLC elements include security champions, bug bounties, and education and training to enhance security throughout the development lifecycle.

4. Application Security Requirements (ISO 27001: 8.26)

This control squarely targets application security. It mandates identifying, specifying, and approving information security requirements during application development or acquisition. Integrating security requirements into your development process ensures that security becomes an integral facet, yielding more secure applications.

The OWASP Application Security Verification Standard (ASVS) provides a comprehensive set of requirements for application security. It covers many topics, including authentication, authorization, input validation, data protection, and session management.

Here are some of the key application security requirements in the OWASP Application Security Verification Standard (ASVS) 4.0:

  • Authentication: The application must use strong authentication mechanisms, such as multi-factor authentication.
  • Authorization: The application must enforce access control policies to ensure that users can only access the resources they are authorized to access.
  • Input validation: The application must validate all user input to prevent malicious attacks, such as cross-site scripting (XSS) and SQL injection.
  • Data protection: The application must protect sensitive data from unauthorized access, disclosure, modification, and destruction.
  • Session management: The application must manage user sessions securely to prevent session hijacking and other attacks.

In addition to these general requirements, the ASVS includes specific requirements for various security topics, such as cryptography, error handling, and logging.

Organizations can use the ASVS to assess their applications' security and identify areas where improvement is needed. The ASVS can also be used to guide the development of new applications and ensure they are secure from the start.

You can find more information about the OWASP Application Security Verification Standard (ASVS) 4.0 here: OWASP Application Security Verification Standard (ASVS) 4.0

5. Secure Coding (ISO 27001: 8.28)

The application of secure coding principles during software development is paramount. Adhering to secure coding practices minimizes the potential introduction of vulnerabilities through flawed code. Instructing your development teams in secure coding practices results in applications that are more resistant to attacks. Sync Provides quick guideline for secure coding summarized here:

Code Minification and Obfuscation: Minifying code by removing white space and line breaks can make it harder to read, deterring potential attackers. Code obfuscation goes further by transforming human-readable code into difficult-to-understand text.

Avoiding Shortcuts: Developers should avoid taking shortcuts, such as leaving hardcoded credentials and security tokens as comments in the code. Such shortcuts can lead to security vulnerabilities, especially in larger code bases and under tight release schedules.

Automated Scanning and Code Reviews: Regular code reviews and automated tools that scan for vulnerabilities, like Cross-Site Scripting (XSS) and SQL injection, can help prevent attacks that exploit code weaknesses.

Avoiding Components with Known Vulnerabilities: While open-source components and libraries can save time, they may introduce vulnerabilities. It's essential to avoid components with known vulnerabilities and monitor for new ones throughout the development process.

Auditing and Logging: Implementing robust logging and monitoring in software allows for detecting potential incidents in a production environment, aiding in maintaining code integrity.

You can find more information here:

6. Security Testing in Development and Acceptance (ISO 27001: 8.29)

Explicitly defining security testing processes and embedding them into the development life cycle is critical. Rigorous testing identifies and rectifies security flaws before applications are deployed. Comprehensive security testing ensures that you do not miss out on any of the above controls and your applications are well-protected against vulnerabilities and emerging threats.

Whether you are a software development company or a third-party user working towards ISO 27001 compliance or just adopting ISO 27001 controls tailored to application security, following these controls can fortify your information security posture, mitigate vulnerabilities, and protect your applications and sensitive data from evolving threats.

Biz Serve IT is a cybersecurity company that provides services that meet your compliance needs and specific application security requirements. Reach out to us at

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