homepage
Open menu
Go one level top
  • Train and Certify
    Train and Certify

    Immediately apply the skills and techniques learned in SANS courses, ranges, and summits

    • Overview
    • Courses
      • Overview
      • Full Course List
      • By Focus Areas
        • Cloud Security
        • Cyber Defense
        • Cybersecurity and IT Essentials
        • DFIR
        • Industrial Control Systems
        • Offensive Operations
        • Management, Legal, and Audit
      • By Skill Levels
        • New to Cyber
        • Essentials
        • Advanced
        • Expert
      • Training Formats
        • OnDemand
        • In-Person
        • Live Online
      • Course Demos
    • Training Roadmaps
      • Skills Roadmap
      • Focus Area Job Roles
        • Cyber Defence Job Roles
        • Offensive Operations Job Roles
        • DFIR Job Roles
        • Cloud Job Roles
        • ICS Job Roles
        • Leadership Job Roles
      • NICE Framework
        • Security Provisionals
        • Operate and Maintain
        • Oversee and Govern
        • Protect and Defend
        • Analyze
        • Collect and Operate
        • Investigate
        • Industrial Control Systems
    • GIAC Certifications
    • Training Events & Summits
      • Events Overview
      • Event Locations
        • Asia
        • Australia & New Zealand
        • Latin America
        • Mainland Europe
        • Middle East & Africa
        • Scandinavia
        • United Kingdom & Ireland
        • United States & Canada
      • Summits
    • OnDemand
    • Get Started in Cyber
      • Overview
      • Degree and Certificate Programs
      • Scholarships
    • Cyber Ranges
  • Manage Your Team
    Manage Your Team

    Build a world-class cyber team with our workforce development programs

    • Overview
    • Why Work with SANS
    • Group Purchasing
    • Build Your Team
      • Team Development
      • Assessments
      • Private Training
      • Hire Cyber Professionals
      • By Industry
        • Health Care
        • Industrial Control Systems Security
        • Military
    • Leadership Training
  • Security Awareness
    Security Awareness

    Increase your staff’s cyber awareness, help them change their behaviors, and reduce your organizational risk

    • Overview
    • Products & Services
      • Security Awareness Training
        • EndUser Training
        • Phishing Platform
      • Specialized
        • Developer Training
        • ICS Engineer Training
        • NERC CIP Training
        • IT Administrator
      • Risk Assessments
        • Knowledge Assessment
        • Culture Assessment
        • Behavioral Risk Assessment
    • OUCH! Newsletter
    • Career Development
      • Overview
      • Training & Courses
      • Professional Credential
    • Blog
    • Partners
    • Reports & Case Studies
  • Resources
    Resources

    Enhance your skills with access to thousands of free resources, 150+ instructor-developed tools, and the latest cybersecurity news and analysis

    • Overview
    • Webcasts
    • Free Cybersecurity Events
      • Free Events Overview
      • Summits
      • Solutions Forums
      • Community Nights
    • Content
      • Newsletters
        • NewsBites
        • @RISK
        • OUCH! Newsletter
      • Blog
      • Podcasts
      • Summit Presentations
      • Posters & Cheat Sheets
    • Research
      • White Papers
      • Security Policies
    • Tools
    • Focus Areas
      • Cyber Defense
      • Cloud Security
      • Digital Forensics & Incident Response
      • Industrial Control Systems
      • Cyber Security Leadership
      • Offensive Operations
  • Get Involved
    Get Involved

    Help keep the cyber community one step ahead of threats. Join the SANS community or begin your journey of becoming a SANS Certified Instructor today.

    • Overview
    • Join the Community
    • Work Study
    • Teach for SANS
    • CISO Network
    • Partnerships
    • Sponsorship Opportunities
  • About
    About

    Learn more about how SANS empowers and educates current and future cybersecurity practitioners with knowledge and skills

    • SANS
      • Overview
      • Our Founder
      • Awards
    • Instructors
      • Our Instructors
      • Full Instructor List
    • Mission
      • Our Mission
      • Diversity
      • Scholarships
    • Contact
      • Contact Customer Service
      • Contact Sales
      • Press & Media Enquiries
    • Frequent Asked Questions
    • Customer Reviews
    • Press
    • Careers
  • Contact Sales
  • SANS Sites
    • GIAC Security Certifications
    • Internet Storm Center
    • SANS Technology Institute
    • Security Awareness Training
  • Search
  • Log In
  • Join
    • Account Dashboard
    • Log Out
  1. Home >
  2. Blog >
  3. Agile Security for Product Owners - Requirements
SANS DevSecOps

Agile Security for Product Owners - Requirements

April 29, 2011

Much of cumulative application security knowledge and tools are aimed at detection, rather than prevention, of vulnerabilities. This is a natural consequence of the fact that the primary job of many information security analysts is to look for security vulnerabilities and provide high level remediation suggestions rather than be involved in detailed remediation efforts. Another reason is that most organizations want to get a grip on what security exposures they currently have before focusing their efforts on preventing future exposures.

The consequence for application owners is that many of the tools that we have at our disposal are focused on vulnerability detection:

  • Static analysis tools
  • Runtime vulnerability scanning tools
  • Verification standards such as the ASVS

Luckily, application security experts have long argued the case for focusing on prevention rather than relying solely relying on detection of security vulnerabilities. Building-in security early in the SDLC is a matter of cost effectiveness. Efforts such as OWASP's Enterprise Security API deal with this issue head-on at the code level. At a higher level, some organizations have developed Secure Software Development Life Cycle models such as the Software Assurance Maturity Model, Building Security In Maturity Model, or Microsoft's SDL.

Comprehensiveness Bias

Most SDLC security initiatives treat security requirements engineering as a foundational activity. The challenge in an Agile/Scrum context is that requirements (i.e. product backlog) are constantly shifting. Iterations are short, intense, and there is little time to introduce new processes such as an architectural analysis, threat risk assessments, or week-long penetration testing.Moreover, if we start with a minimal functionality system as Agile methodologies suggest then we can rarely, in practice, introduce all security requirements at one time. As an agile product owner, you are confronted with mountains of secure SDLC best practices that work best when you have a complete set of requirements up front: the antithesis of agile processes.

The Security Burden

Suppose you're near the inception of a new product or major re-release and you have short iterations. Looking at your product backlog, you likely have several months of tickets/detects/stories that represent mostly functional requirements. Ideally you've carefully groomed the backlog and prioritized items according to their importance in building a minimally functional system and their perceived benefit to end users.

Now let's say you want to add security requirements. Based on personal experience consulting at Security Compass and researching for SD Elements, I'd estimate that most large-scale enterprise web applications will have security requirements with a cumulative total of several months of effort. Simply put, you'll be unable to fulfill all security requirements in one shot. In addition, excessive focus on a non-functional concern like security makes it challenging to show incremental value to stakeholders (unless your stakeholders care deeply about security). As a result, you'll be faced with a somewhat ugly reality of agile development on new projects: Given sufficient visibility into security requirements, an agile application will have known security gaps in its early iterations.

You could defy the odds by focusing on security and not releasing the product until all known security gaps have been addressed. The reality, particularly for anyone operating in a competitive environment where security is not one of the top organizational priorities, is that time-to-market pressures make this infeasible.

Incremental Security

Like everything else in the product backlog you must prioritize security requirements. The Software Assurance Maturity Model spells this fact out explicitly:

"It is important to not attempt to bring in too many best-practice requirements into each development iteration since there is a time trade-off with design and implementation. The recommended approach is to slowly add best-practices over successive development cycles to bolster the software's overall assurance profile over time."

There are a couple of caveats you should keep in mind when prioritizing security requirements:

  • Choose risk reduction over perceived customer utility: When developers demonstrate their increment of progress at the end of the iteration, the security requirements will generally be about as visible as refactoring class names unless you actually perform penetration testing. I say generally because there are some cases where security is visible. For example, you might be tempted to add OAuth support in the names of both security and usefulness for end users. The problem is that while OAuth might help improve your security posture, you may have a much more pressing security risk such as ensuring your confidential data is sent over SSL. If you've resolved to build security into your product, choose risk reduction over customer utility for security requirements.
  • Differentiate between features: In the nomenclature of security defects, Dr. Gary McGraw provides a useful distinction between flaws and bugs: 
"Bug (implementation) A software security defect that can be detected locally through static analysis . Flaw (design). 
  • A software security defect at the architecture or design level. Flaws may not be apparent given only source code of a software system."The way you treat the corresponding controls is important
    • Flaw mitigations do belong in a product backlog. They have acceptance criteria and they need to be prioritized amongst all other requirements. These include issues such as authentication, centralized authorization routines, and session management.Once you've figured out which requirements are flaw mitigations you can perform a second level of differentiation: which requirements prevent an exploitable vulnerability versus which requirements provide defense in depth. Block brute force attacks prevents an exploitable vulnerability. Hiding verbose error messages is a measure of defense in depth. You should set your sights on the first group as a priority. Strive for your application to not be vulnerable to any remotely exploitable vulnerabilities as soon as it stores, processes, or transmits production data. Depending on your risk profile, you may also need to consider locally exploitable vulnerabilities to the server and/or compliance-driven requirements that may not accurately reflect risk. If you're lucky enough to start with non-production data then you have the latitude to build these controls across several iterations. However, once your application has production data you are knowingly putting your organization and (if applicable) your clients data at risk if the application lacks known security controls. If you must accept that you'll have exploitable security vulnerabilities, always compare the levels of risk that each security control provides and prioritize for the most significant risk reduction.
    • Bug mitigations generally don't belong on your product backlog because they don't have one-time acceptance criteria; these mitigations have to be addressed in every iteration. You ought to be thinking of them at all times. These are issues like proper output escaping, safe library usage, variable binding in SQL statements, or making sure you don't log confidential data; they are cross-cutting concerns that amount to following coding conventions. Developer education and code review / static analysis are the best ways to eradicate bugs.

In Summary

As a product owner you have scores of tools and processes to help you find vulnerabilities after they've been coded. Adopting security throughout the SDLC is cost effective, but difficult in practice to implement for agile shops. Security requirements, in particular, are difficult to prioritize or scope in early iterations. You can make the task more manageable by prioritizing requirements that prevent exploitable flaws, sorted by risk.

Share:
TwitterLinkedInFacebook
Copy url Url was copied to clipboard
Subscribe to SANS Newsletters
Receive curated news, vulnerabilities, & security awareness tips
United States
Canada
United Kingdom
Spain
Belgium
Denmark
Norway
Netherlands
Australia
India
Japan
Singapore
Afghanistan
Aland Islands
Albania
Algeria
American Samoa
Andorra
Angola
Anguilla
Antarctica
Antigua and Barbuda
Argentina
Armenia
Aruba
Austria
Azerbaijan
Bahamas
Bahrain
Bangladesh
Barbados
Belarus
Belize
Benin
Bermuda
Bhutan
Bolivia
Bonaire, Sint Eustatius, and Saba
Bosnia And Herzegovina
Botswana
Bouvet Island
Brazil
British Indian Ocean Territory
Brunei Darussalam
Bulgaria
Burkina Faso
Burundi
Cambodia
Cameroon
Cape Verde
Cayman Islands
Central African Republic
Chad
Chile
China
Christmas Island
Cocos (Keeling) Islands
Colombia
Comoros
Cook Islands
Costa Rica
Croatia (Local Name: Hrvatska)
Curacao
Cyprus
Czech Republic
Democratic Republic of the Congo
Djibouti
Dominica
Dominican Republic
East Timor
East Timor
Ecuador
Egypt
El Salvador
Equatorial Guinea
Eritrea
Estonia
Ethiopia
Falkland Islands (Malvinas)
Faroe Islands
Fiji
Finland
France
French Guiana
French Polynesia
French Southern Territories
Gabon
Gambia
Georgia
Germany
Ghana
Gibraltar
Greece
Greenland
Grenada
Guadeloupe
Guam
Guatemala
Guernsey
Guinea
Guinea-Bissau
Guyana
Haiti
Heard And McDonald Islands
Honduras
Hong Kong
Hungary
Iceland
Indonesia
Iraq
Ireland
Isle of Man
Israel
Italy
Jamaica
Jersey
Jordan
Kazakhstan
Kenya
Kiribati
Korea, Republic Of
Kosovo
Kuwait
Kyrgyzstan
Lao People's Democratic Republic
Latvia
Lebanon
Lesotho
Liberia
Liechtenstein
Lithuania
Luxembourg
Macau
Macedonia
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands
Martinique
Mauritania
Mauritius
Mayotte
Mexico
Micronesia, Federated States Of
Moldova, Republic Of
Monaco
Mongolia
Montenegro
Montserrat
Morocco
Mozambique
Myanmar
Namibia
Nauru
Nepal
Netherlands Antilles
New Caledonia
New Zealand
Nicaragua
Niger
Nigeria
Niue
Norfolk Island
Northern Mariana Islands
Oman
Pakistan
Palau
Palestine
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Pitcairn
Poland
Portugal
Puerto Rico
Qatar
Reunion
Romania
Russian Federation
Rwanda
Saint Bartholemy
Saint Kitts And Nevis
Saint Lucia
Saint Martin
Saint Vincent And The Grenadines
Samoa
San Marino
Sao Tome And Principe
Saudi Arabia
Senegal
Serbia
Seychelles
Sierra Leone
Sint Maarten
Slovakia
Slovenia
Solomon Islands
South Africa
South Georgia and the South Sandwich Islands
South Sudan
Sri Lanka
St. Helena
St. Pierre And Miquelon
Suriname
Svalbard And Jan Mayen Islands
Swaziland
Sweden
Switzerland
Taiwan
Tajikistan
Tanzania
Thailand
Togo
Tokelau
Tonga
Trinidad And Tobago
Tunisia
Turkey
Turkmenistan
Turks And Caicos Islands
Tuvalu
Uganda
Ukraine
United Arab Emirates
United States Minor Outlying Islands
Uruguay
Uzbekistan
Vanuatu
Vatican City
Venezuela
Vietnam
Virgin Islands (British)
Virgin Islands (U.S.)
Wallis And Futuna Islands
Western Sahara
Yemen
Yugoslavia
Zambia
Zimbabwe

By providing this information, you agree to the processing of your personal data by SANS as described in our Privacy Policy.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Tags:
  • DevSecOps

Related Content

Blog
powershell_option_340x340.jpg
Cyber Defense, DevSecOps, Digital Forensics and Incident Response, Cybersecurity and IT Essentials, Penetration Testing and Red Teaming
July 15, 2022
Month of PowerShell: Working with PowerShell Log Files
In this article we'll look at how we can leverage PowerShell's object-passing pipeline to parse and retrieve data from an IIS web server log file.
370x370_Joshua-Wright.jpg
Joshua Wright
read more
Blog
CloudSecNext Summit Visual Summary
Cloud Security, DevSecOps
May 3, 2022
A Visual Summary of SANS CloudSecNext Summit 2022
On May 3-4, thousands from around the globe tuned in for the SANS CloudSecNext Summit. We invited Ashton Rodenhiser to create graphic recordings of our Summit presentations. If you missed a talk or are looking to view the SANS CloudSecNext Summit through a visual lens, take a look at the recordings...
370x370-person-placeholder.png
Alison Kim
read more
Blog
DevSecOps
May 4, 2015
2015 State of Application Security: Closing the Gap
The 2015 SANS State of Application Security Analyst Paper and webcasts are complete. This year, Jim Bird, the lead author of the SANS Application Security Survey series, Frank Kim, and I all participated in writing the questions, analyzing the results, drafting the paper, and preparing the webcast...
Eric_Johnson_370x370.png
Eric Johnson
read more
  • Register to Learn
  • Courses
  • Certifications
  • Degree Programs
  • Cyber Ranges
  • Job Tools
  • Security Policy Project
  • Posters & Cheat Sheets
  • White Papers
  • Focus Areas
  • Cyber Defense
  • Cloud Security
  • Cybersecurity Leadership
  • Digital Forensics
  • Industrial Control Systems
  • Offensive Operations
Subscribe to SANS Newsletters
Receive curated news, vulnerabilities, & security awareness tips
United States
Canada
United Kingdom
Spain
Belgium
Denmark
Norway
Netherlands
Australia
India
Japan
Singapore
Afghanistan
Aland Islands
Albania
Algeria
American Samoa
Andorra
Angola
Anguilla
Antarctica
Antigua and Barbuda
Argentina
Armenia
Aruba
Austria
Azerbaijan
Bahamas
Bahrain
Bangladesh
Barbados
Belarus
Belize
Benin
Bermuda
Bhutan
Bolivia
Bonaire, Sint Eustatius, and Saba
Bosnia And Herzegovina
Botswana
Bouvet Island
Brazil
British Indian Ocean Territory
Brunei Darussalam
Bulgaria
Burkina Faso
Burundi
Cambodia
Cameroon
Cape Verde
Cayman Islands
Central African Republic
Chad
Chile
China
Christmas Island
Cocos (Keeling) Islands
Colombia
Comoros
Cook Islands
Costa Rica
Croatia (Local Name: Hrvatska)
Curacao
Cyprus
Czech Republic
Democratic Republic of the Congo
Djibouti
Dominica
Dominican Republic
East Timor
East Timor
Ecuador
Egypt
El Salvador
Equatorial Guinea
Eritrea
Estonia
Ethiopia
Falkland Islands (Malvinas)
Faroe Islands
Fiji
Finland
France
French Guiana
French Polynesia
French Southern Territories
Gabon
Gambia
Georgia
Germany
Ghana
Gibraltar
Greece
Greenland
Grenada
Guadeloupe
Guam
Guatemala
Guernsey
Guinea
Guinea-Bissau
Guyana
Haiti
Heard And McDonald Islands
Honduras
Hong Kong
Hungary
Iceland
Indonesia
Iraq
Ireland
Isle of Man
Israel
Italy
Jamaica
Jersey
Jordan
Kazakhstan
Kenya
Kiribati
Korea, Republic Of
Kosovo
Kuwait
Kyrgyzstan
Lao People's Democratic Republic
Latvia
Lebanon
Lesotho
Liberia
Liechtenstein
Lithuania
Luxembourg
Macau
Macedonia
Madagascar
Malawi
Malaysia
Maldives
Mali
Malta
Marshall Islands
Martinique
Mauritania
Mauritius
Mayotte
Mexico
Micronesia, Federated States Of
Moldova, Republic Of
Monaco
Mongolia
Montenegro
Montserrat
Morocco
Mozambique
Myanmar
Namibia
Nauru
Nepal
Netherlands Antilles
New Caledonia
New Zealand
Nicaragua
Niger
Nigeria
Niue
Norfolk Island
Northern Mariana Islands
Oman
Pakistan
Palau
Palestine
Panama
Papua New Guinea
Paraguay
Peru
Philippines
Pitcairn
Poland
Portugal
Puerto Rico
Qatar
Reunion
Romania
Russian Federation
Rwanda
Saint Bartholemy
Saint Kitts And Nevis
Saint Lucia
Saint Martin
Saint Vincent And The Grenadines
Samoa
San Marino
Sao Tome And Principe
Saudi Arabia
Senegal
Serbia
Seychelles
Sierra Leone
Sint Maarten
Slovakia
Slovenia
Solomon Islands
South Africa
South Georgia and the South Sandwich Islands
South Sudan
Sri Lanka
St. Helena
St. Pierre And Miquelon
Suriname
Svalbard And Jan Mayen Islands
Swaziland
Sweden
Switzerland
Taiwan
Tajikistan
Tanzania
Thailand
Togo
Tokelau
Tonga
Trinidad And Tobago
Tunisia
Turkey
Turkmenistan
Turks And Caicos Islands
Tuvalu
Uganda
Ukraine
United Arab Emirates
United States Minor Outlying Islands
Uruguay
Uzbekistan
Vanuatu
Vatican City
Venezuela
Vietnam
Virgin Islands (British)
Virgin Islands (U.S.)
Wallis And Futuna Islands
Western Sahara
Yemen
Yugoslavia
Zambia
Zimbabwe

By providing this information, you agree to the processing of your personal data by SANS as described in our Privacy Policy.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
  • © 2023 SANS™ Institute
  • Privacy Policy
  • Contact
  • Careers
  • Twitter
  • Facebook
  • Youtube
  • LinkedIn