CISO AppSec Guide: Application Security Program
- 1 Part III: Selection of Application Security Processes
- 1.1 Introduction
- 1.2 Addressing CISO's Application Security Functions
- 1.3 Targeting Software Security Activities and S-SDLC Processes
- 1.4 How to Choose the Right OWASP Projects and Tools For Your Organization
Part III: Selection of Application Security Processes
Mitigating the risk of attacks that seek to exploit of application vulnerabilities as well as potential gaps in protective and detective controls is one of the CISOs main concerns. In the case when vulnerability is only found after a security incident occurred, the next step is to fix the vulnerability and limit further impact. Typically this involves retesting of the vulnerability and make sure is being fixed so ca no longer be exploited in the future. If the incident is due to a gap of a security control such as for example a failure to filter malicious input or to detect the attack event, the next logical step is to implement a countermeasure to mitigate the risk. To makes such decisions, the CISO need to consider both the risks of vulnerabilities as well as the weaknesses of security control measures to make a decision on how to mitigate the risks. Typically fixing a vulnerability involves a vulnerability management cycle that includes identifying the vulnerability, fixing it and then re-testing it to determine that is no longer present.
In case of countermeasures the test that the countermeasure is effective in preventing and detecting an attack vector can also be tested with a functional security test after countermeasure is deployed. The decision to which countermeasure to deploy might depend on different factors such as the cost of the countermeasure vs. the business impact of the incident as well as on how risk mitigation effective is the countermeasure by comparing with others. The next step for the CISO after the security incident is under control is to make sure any vulnerabilities are fixed and countermeasures are deployed to mitigate the risk. In this section of the guide we focus on application security measures that are most cost effective to target the issues identified in Part 2. For example how to divide budgets across software security activities such as secure code training, secure code reviews, secure verification/test and issue and risk management". The results of the CISO survey will be used to determine where money is spent and in which activities to determine if application security money is spent effectively (e.g. focus on security build in activities vs security bolt-on security activities). The results of the CISO survey will also be used to identify if standard application security controls are used to highlight which OWASP objects are most useful (e.g. SAMM, ESAPI, CLASP, Security Development, Coding and Testing Guides) "
Addressing CISO's Application Security Functions
Application Security Governance, Risk and Compliance
Governance is the process that introduce policies, standards, processes and sets the strategy, goals and organizational structure to support them. At operational level, governance, compliance and risk management are interrelated. As part of governance responsibilities, CISOs influence the application security goals and work with executive management to set the application security standards, processes and organizational structure to support these goals. As part of compliance responsibilities, CISOs work with auditors and the legal counsel to derive information security policies and establish requirements to comply, measure and monitor these requirements including application security requirements. As part of risk management responsibilities, CISOs identify, quantify and make risk evaluations to determine how to mitigate application security risks that includes introducing new application security standards and processes (governance), new application security requirements (compliance) and new application security measures (risks and controls).
From governance perspective, the adoption of application and software security processes, the establishment of application security teams and application security standards within any given organization varies greatly depending on the type of the organization’s industry, the size of the organization and the different roles and responsibility that the CISO has in that organization. The source of application security investments also varies depending on the size and the type of the organization. For CISOs reporting to the organization's head of operational information security and risk management, typically the budget for application security is part of the overall budget allocated by information security and operational risk departments. For these CISOs, one the main reasons for the adoption of new application security activities, guides and tools such as the ones that OWASP provides, is first and for the most to satisfy compliance and to reduce risks to the organization’s assets such as applications and software. Compliance varies greatly depending on the type of industry and clients served by the organization. For example, organizations that produces software that implements cryptography for use by governments such as the department and agencies of the United States Federal government need to comply with Federal Information Processing Standards (FIPS) 140. Organizations that produce software and applications that handle cardholder data such credit and debit card data for payments need to comply with is the Payment Card Industry Data Security Standard (PCI DSS).
CISOs that report to the organization's head of information technology, typically have responsibility on both security and information technology functions that might also include the compliance of applications and software with technology security standards such as FIPS 140 and PCI-DSS. Compliance with security technology standards represent an opportunity for promoting secure development and testing within the organization such as by using OWASP security testing guides for achieving security certifications for applications and software products. Compliance with PCI-DSS requirements for example might already require the organization to test applications for a minimum set of common vulnerabilities such as the OWASP Top 10. The budget allocated by the IT department for achieve certifications with technology security standards such as FIPS-140 and PCI-DSS can also be used for promoting secure coding guides such as the OWASP secure coding guide and invest on static code analysis tools. For example, in the case of compliance with PCI-DSS, CISOs might opt for static code analysis to satisfy the requirement 6.6 of PCI-DSS. CISOs of small organizations can also use defect management metrics to make the business case in which phases of the SDLC to invest in security and improve both software quality as well as security. For example, since most of the quality and security bugs are due coding errors, it is important for CISOs to emphasize to the IT department the need of secure coding processes, standards and training for developers since focusing on these software security activities also leads to cost savings for the organization. A study from NIST about the cost of fixing security issues for example has shown that the cost of fixing a coding issue in production is six times more expensive than fixing it during coding. To achieve these money saving and efficiency goals, CISOs can work together with the engineering department managers to promote application and secure software initiatives.
For CISOs whose main focus is information security and risk management, one of the main requirements besides compliance is to introduce efficiencies and save the money spent for existing security processes, including, application security. Since the information security department allocates budgeting, any request for budget of application security need to be justified by improving security and by reducing risks. Security and risk reduction goals are aligned by improving security test processes with use of better tools and training for developers. For CISOs of large organizations, promoting a software security initiative is also justified by the return of investment in the overall application security program and processes, specifically as reduction in the cost of fixing vulnerabilities because of developers following secure coding standards, conducting secure code reviews and security teams conducting security testing for vulnerabilities earlier than the validation phase of the SDLC. OWASP provides secure development guides and secure coding guides as well as training modules that can be used to achieve this cost saving goals. Often CISOs need to justify the budget for application security by taking into consideration the different needs of security and business departments. For CISOs that serve in financial organizations for example, security is often a compromise with security and business goals. In this case, it is important for CISOs to be able to align application security programs with the business goals and when these goals not align, to focus on the ones that do. For example, by focusing on improving both software quality and security and by reaching a compromise in the case security impacts negatively the customer experience so different security options need to be considered. In the case the business is sponsoring a new application development project, CISOs can use this as an opportunity to promote new application security features for the application and work together with project managers by achieving compliance with security standards, improving security by design and by coding and yet achieving overall cost savings for the overall project.
The Importance of Security Metrics
For CISOs whose responsibility is manage application vulnerability risks, security metrics such as application vulnerability metrics constitutes an important factor in making business cases for investing in application security measures to control and reduce risks. Security metrics such as measurements of vulnerabilities found on the same applications during the roll out of application security activities aimed to reduce the number and the risk of vulnerabilities for example, can demonstrate to senior managers and company executives that the adoption of application security processes, training and tools ultimately helps the organization to deliver applications and software products that have a fewer number of vulnerabilities and pose less risk to the organization and the customers.
Targeting Software Security Activities and S-SDLC Processes
Recognizing Importance and Criticality of Secure Software
Since a large number of vulnerabilities in applications are caused by insecure coding, it is important that the CISO recognizes the importance that secure software has in improving the security of the application. The causes of insecure software might depends by different factors such as coding errors, not following secure coding standards and security requirements, integration with vulnerable software libraries, missing secure code review processes and security testing and formal secure code training and awareness for software developers. From CISO perspective, it is important to understand that software security is a complex discipline and requires a special focus in security processes, tools as well as people skills. It is also important to recognize that investing in software security helps the organization to save money spent in application vulnerability remediation costs in the future. By investing in software security initiatives, organizations can focus on fixing vulnerabilities as early as during coding phase of the Software Development Life-Cycle (SDLC) where is cheaper to identify, test and fix them than during the validation phase.
Today, also thanks to OWASP, software security has matured and evolved as a discipline. For example, several organizations already adopt software security best practices within their software development processes such as the documentation of security requirements, following of secure coding standards and use of software security testing tools such as static source code analysis tools to identify vulnerabilities in source code before releasing source code to be build and integrated for final integrated and user acceptance tests. By integrating software security activities in the SDLC, organizations can produce software and applications with a fewer number of vulnerabilities and lower risks than software and applications that don’t.
Integrating Risk Management as part of The SDLC
The question for CISO is rather not IF but WHICH and HOW software security activities can be integrated as part of the SDLC. According to the National Institute of Standards and Technology’s Special Publication 800-30, “Effective risk management must be totally integrated into the SDLC ... [which] has five phases: initiation, development or acquisition, implementation, operation or maintenance and disposal.” The integration of security in the SDLC process begins by identifying the information assets that the software will be processing and by specifying requirements for confidentiality, integrity and availability. The next step consists on the determining the value of information assets, identifying the potential threats and determine the requirements for application security controls such as authentication, authorization and encryption to protect the confidentiality, integrity and availability of the data assets.
A comprehensive set of security requirements need to also include requirements to implement secure software by following certain security and technology standards, security approved technologies and platforms as well as security checks prior of software integration with other vendors software components/libraries.
Assess Risks before Procurement of Third Party Components
When software is acquired as either part of the commercial off-the-shelf (COTS) or as free open source (FOSS) for example, it is important for CISO to have a process in place to validate this type of software libraries against specific security requirements prior to acquiring them. This could provide the CISO of the organization a certain level of assurance that the acquired software is secure and can be integrated with the application. In that regard, OWASP had developed a legal project and a contract annex of a sample contract that included security requirements for the life cycle so that COTS products would be more secure.
Security in the SDLC (S-SDLC) Methodologies
In cases when the CISO of the organization has also responsibility over promoting a software security process within the organization, it is important not to take this goal lightly since usually requires careful planning of resources and development of new processes and activities. Fortunately today, several “Security in the SDLC” (S-SDLC) methodologies can be adopted by CISOs to incorporate security in the SDLC. The most popular S-SDLC methodologies used today are Cigital’s Touch Points, Microsoft SDL and OWASP CLASP. At high level, these S-SDLC methodologies are very similar and consist on integrating security activities such as security requirements, secure architecture review, architecture risk analysis/threat modeling, static analysis/review of source code, security/penetration testing activities within the existing SDLCs used by the organization. The challenge for the integration of security in the SDLC from CISO perspective is to make sure that these software security activities are aligned with the software engineering processes used by the organization. This means for example to integrate with different types of S-SDLC s such as Agile, RUP, Waterfall as these might be already followed by different software development teams within the organization. An example on how these can be integrated within a waterfall SDLC as well as iterated within different iterations of a SDLC process is shown herein
From CISO perspective, adopting a holistic approach toward application and software security leads to better results since can align with information security and risk management already adopted by the organization.. From information security perspective, the holistic approach toward application security should include for example security training for software developers as well as security officers and managers, integration with information security and risk management, alignment with information security policies and technology standards and leveraging of information security tools and technologies used by the organization.
Software Assurance Maturity Models
Besides of following a holistic approach toward application security that considers other domains it is also important for the CISO to consider what the organization capabilities are from day one in building software security and plan on how to integrate new activities in the future. Measuring the organizations capabilities in software security is possible today with software security maturity models such as the Build Security In Maturity Model (BSIMM) and the Software Assurance Maturity Model (SAMM). These models can also help the CISO in the assessment, planning and implementation of a software security initiative for the organization. These maturity models are explicitly designed for software security assurance. These models, even if are based upon empirical measurements, are feed from real data (e.g. software security surveys) hence allow to measure organizations against peers that already had implemented software security initiatives. By allowing their organization’s secure software development software practices to be measured using these models, CISOs can compare their organization secure software development capabilities against other software development organizations to determine in which software security activities the organization either leads or lags.
For the software security activities for which the organization is lagging, BSIMM and SAMM measurements allow the CISO to construct a plan for software security activities to close these gaps in the future. It is important to notice that these models are not prescriptive that is, are not telling organizations what to do but rather to measure security activities in comparison with similar organizations in the field. The models are organized along similar domains, governance, intelligence, SSDL touch points, deployment for BSIMM and governance,construction, verification, deployment for SAMM. SAMM measurements are done in three best practices and three levels of maturity for each business function. The business functions and the security practices for each business function are shown in the figure herein:
BSIMM measurements cover 12 best practices and 110 software security activities. The maturity levels help the CISO to plan for the organizational improvements in software security processes. Software security improvements can be measured by assigning goals and objectives to reach for each activity. For CISOs that either have already started to deploy a software security initiative such as S-SDLC within their organization or that just plan it in the future, the measurements that a model such as BSIMM and SAMM provide are important measurement yard sticks to determine in which application security activities to focus spending. If not already familiar with BSIMM and SAMM, CISOs can also refer to the Capability Maturity Model (CMM) and the various maturity levels to plan for the organization secure software development process capabilities.
Like BSIMM and SAMM, CMM is also an empirical model whose goal is improve the predictability, effectiveness, and control of an organization's software processes. In CMM for example, these are five levels that can be used to measure how the organization moves up to different levels of maturity of software engineering process: initial, repeatable, defined, managed, optimizing. In the first level (initial), the software engineering process is ad-hoc and used by the organization in uncontrolled and reactive manner. As the software development organization reaches level 2, the software development processes are repeatable and is possible to provide consistent results. When an organization reaches level 3, it means that it has adopted a set of defined and documented standard software development processes and these are followed consistently across the organization. At a level 4, that is managed, a software development organization has adopted metrics and measurements so that software development can be managed and controlled. When a software development organization is at level 5, optimized, the focus is on continually improving process performance through both incremental and innovative technological change and improvements in software development.
In reference to software security processes, at CMM Level 1 (Initial) CISOs have an ad-hoc process to “catch” and "patch" application vulnerabilities. At this level, the organization maturity in software security practice consists on running web application vulnerability scanning tool in reaction of events such as to validate the applications for compliance with PCI-DSS and OWASP Top 10. At CMM Level 2, the organization has already adopted standard processes for security testing applications for vulnerabilities including secure code reviews of the existing software libraries and components. At this level, the secure testing process can be repeated to produce consistent results (e.g. get same security issues if executed by different testers) but is not adopted across all software development groups within the same organization. At CMM Level 2, the application security processes are also reactive, that is, are not executed as required by the security testing standards. At CMM Level 3, application security processes are executed by following defined process standards and these are followed by all security teams within the same organization. At this level, application security processes are also proactive that means are executed to security test applications as part of governance, risk and compliance requirements prior to release into production. At level CMM 4 (managed) application security risks are identified and managed at different phases of the SDLC. At this level, the focus of security is the reduction of risks for all applications before these are released in production. At level CMM 5 (optimized), the application security processes are optimized for increased application coverage and for the highest return of investments in application security activities.
How to Choose the Right OWASP Projects and Tools For Your Organization
Depending on the overall security level and risk profile of the organization unit different tools and standards can be particularly useful for the CISO in advancing his security strategy. Note, following the risk discussions in the previous chapter, depending on the risk profile of different business units, the security strategy can actually be different based on their different individual risk scenarios and different regulatory requirements. For example a financial department may require a substantially stronger security posture, while an internal web page announcing the lunch menus of the cantine may be sufficiently protected with basic security measures (though to the authors knowledge in military settings, even the lunch menu can be considered as confidential information as further information about supply logistics etc. could be derived from that). Based on these different risk profiles different tools and standards may be more relevant for the project and organizational unit in question. In general tools can be classified in various categories (and so are also the OWASP projects):
- Stable (a project or tool that is mature and constantly maintained to a good quality) - Beta (relatively proven, though not to optimal quality) - Alpha (this usually reflects a good first prototype, but still a lot of functionality may be missing or not up to standard) - Inactive (former projects that have been retired or deprecated or that at some point have been abandoned). Obviously for a CISO, the most interesting projects and tools would be stable and reliable ones. He can rely on a certain proven quality, and on them being available and maintained to a certain degree in the future days to come. Beta projects can also be very valuable, as they may represent projects that have not finished their full review cycle yet but are already available for early adopters and can help to build good foundations for your security programs and tools going forward.
A second dimension would be the various:
Usually OWASP projects are divided in either Tools or Documentation. And by the category of use: Protect, Detect and Life Cycle. These categories can help the manager to quickly navigate the large portfolio of OWASP tools available and more easily find the right project for his current needs. Please find a page of the various OWASP projects classified by categories here.
People, Processes and Technology
The CISO can also choose to achieve his security goals through three main ways. People, Processes and Technology. Managing the organization it is usually important to shape all three pillars to achieve the best impact throughout your organization. Focusing on only one or two of them can leave the organization vulnerable.
This will address the training and motivation of staff, suppliers, clients and partners. If they are well educated and motivated, the chances of malicious behavior or accidental mistakes can dramatically be reduced and many basic security threats can be avoided.
If an organization becomes more mature, the processes will be well defined and in fact channel and enable the work force to do things the "right way". Processes can ensure that the actions of the organization became reliable and repeatable. For example with well-defined standard operating procedures, the incident response process will be reliable and not rely on ad hoc decisions that would before have varied with the individual decision maker. In highly mature organizations, the business and IT processes will be constantly evaluated and improved. If a failure happens, improved processes can allow an organization as a whole to learn from past mistakes and improve its operation to more efficient and secure ways.
In general technology can guide and support people by providing good training and knowledge, by being engaging and motivating to work with. And Technology can enable an organization to make the following the right processes easy by providing good tools, while making it hard to deviate from the right path for malicious users. For example good technology would automate access controls and authentication and make them very simple for the authorized user, while denying access or privileges to an unauthorized attacker. And last but not least a number of automated tools can in the background help and support the people and organization in their work to defend against risks more effectively and more efficiently. Many of the security standards and tools (in OWASP and other bodies) can also be seen as focusing on parts of this framework. For example, staff training will enable the people to build their security understanding and do the right thing, while the various SDLC models can help an organization establish the right level of processes for its development and incident response mechanisms.
Benchmarking & Maturity
One of the very first steps for a CISO is to understand his current situation by reviewing the current security maturity of his organization or the individual department and benchmark it against peers or his target security posture.
There are several maturity models published, with variations in focus and depth of detail. Usually they share a number of good practices and for a CISO it may be advisable to review whether his organization is elsewhere already using one of the maturities models and possibly align with this for an easier initial benchmark of his organization. In the medium term the decision for which maturity model to use, would be driven be question of: what level of detail is required, are we required by a regulatory body to use and report based on a specific type of maturity model, can our model be easily integrated with the organization’s culture and common reporting information, ... In the end, the author believes that most maturity models can equally fulfill your basic needs and that it will be up to the tactical judgment of the CISO to decide which model to use. The openSAMM maturity model has in the past been developed by OWASP and is a very mature ("stable") project, that offers a fairly lightweight way in analyzing your current security maturity and benchmarking your organization against your peers and your targets. See also: Software Assurance Maturity Models (SAMM), OWASP, http://www.opensamm.org/ Other maturity models can be taken from BSIMM, CMM (Common Maturity Model), the ISO-2700x series