Security For Application Development


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Web Application Security for developers. This presentation gives an overview of the OWASP Top 10 and Threat Modeling

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Security For Application Development

  1. 1. An Overview of the OWASP Top Ten and Threat Modeling 12/17/2013 Mike Tetreault, CISSP, CSSLP 1
  2. 2. Introduction  Who is Mike Tetreault?  Over twenty years of IT experience  Primarily applications, but also includes network, server, and database administration  Security background  Lifelong interest in physical and data security  Security is the one constant across all of my roles  Certification Activities ○ 2003 – Certified Information Systems Security Professional (CISSP) ○ 2008 – Microsoft Certified Information Technology Professional – SQL Server 2005 ○ 2009 – Certified Secure Software Lifecycle Professional (CSSLP) ○ 2013 – Passed Healthcare Information Security and Privacy Practitioner (HCISPP) exam 12/17/2013 Mike Teterault, CISSP, CSSLP 2
  3. 3. Presentation Overview  Why focus on web applications?  We all have them and we all use them  This is why they have the largest threat profile  Why are web applications everywhere?  Quickly installed and updated  Work across devices and operating systems  Why is this bad?  Data is accessible from anywhere  Clients do some hidden processing  This is what leads to vulnerabilities 12/17/2013 Mike Teterault, CISSP, CSSLP 3
  4. 4. Why It Matters According to the 2013 Global Information Security Workfors Study by (ISC)2, 69% of the over 12,000 IT professionals surveyed believe that application vulnerabilities are the number one security issue for 2013.  Yahoo CISO departed in January 2013 in wake of a massive Cross Site Scripting (XSS) attack that turned Yahoo Mail into a spam factory.  Heartland Payment Systems suffered a SQL injection attack in 2008 which cost them $170 million, by their own admission.  2013 Ponemon Institute puts the overall cost of a data breach at $188 per record.  12/17/2013 Mike Teterault, CISSP, CSSLP 4
  5. 5. OWASP Top Ten For 2013 Injection Sensitive Data Exposure Broken Data Authentication and Session Management Missing Function Level Access Control Cross-Site Scripting (XSS) Cross-Site Request Forgery Insecure Direct Object References Using Components With Known Vulnerabilities Unvalidated Redirects and Forwards Security Misconfiguration 12/17/2013 Mike Teterault, CISSP, CSSLP 5
  6. 6. A1: Injection  What it is:  Injection flaws, such as SQL, OS, and LDAP injection occur when untrusted data is sent to an interpreter as part of a command or query. The attacker’s hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization.  What it looks like:  String query = "SELECT * FROM accounts WHERE custID='" + request.getParameter("id") + "'";  How to mitigate:  Keep untrusted data separate from commands and queries.  Use a safe API with parameterized inputs.  Scrub inputs to escape special characters (eg, SQL’s ‘:’ operator). 12/17/2013 Mike Teterault, CISSP, CSSLP 6
  7. 7. How Popular is SQL Injection? 12/17/2013 Mike Teterault, CISSP, CSSLP 7
  8. 8. A2: Broken Data Authentication and Session Management  What it is:  Application functions related to authentication and session management are often not implemented correctly, allowing attackers to compromise passwords, keys, or session tokens, or to exploit other implementation flaws to assume other users’ identities.  What it looks like:  waii  How to mitigate:  Use a single set of strong authentication and session management controls that has a simple interface for developers.  Strong efforts should also be made to avoid Cross-Site Scripting (XSS) flaws which can be used to steal session IDs. 12/17/2013 Mike Teterault, CISSP, CSSLP 8
  9. 9. A3: Cross-Site Scripting (XSS)  What it is:  XSS flaws occur whenever an application takes untrusted data and sends it to a web browser without proper validation or escaping. XSS allows attackers to execute scripts in the victim’s browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites.  What it looks like:  page += "<input name='creditcard' type='TEXT' value='" + request.getParameter("CC") + "'>";  How to mitigate:  Properly escape all untrusted (ie, user supplied) data based on the HTML context (body, attribute, JavaScript, CSS, or URL) that the data will be placed into. 12/17/2013 Mike Teterault, CISSP, CSSLP 9
  10. 10. A4: Insecure Direct Object References  What it is:  A direct object reference occurs when a developer exposes a reference to an internal implementation object, such as a file, directory, or database key.  What it looks like:  Valid:  Not Valid:  How to mitigate:  Use per-user or per-session indirect references. ○ This means that the reference is only valid for a single user or session, and means nothing to a different user or session. 12/17/2013 Mike Teterault, CISSP, CSSLP 10
  11. 11. A5: Security Misconfiguration  What it is:  Good security requires having a secure configuration defined and deployed for the application, frameworks, application server, web server, database server, and platform. Secure settings should be defined, implemented, and maintained, as defaults are often insecure. Additionally, software should be kept up to date.  How to mitigate:  Maintain a repeatable hardening process that makes it fast and easy to deploy another environment that is properly locked down.  Implement a process for keeping abreast of and deploying all new software updates and patches in a timely manner. 12/17/2013 Mike Teterault, CISSP, CSSLP 11
  12. 12. A6: Sensitive Data Exposure  What it is:  Many web applications do not properly protect sensitive data. Attackers may steal or modify such weakly protected data to conduct credit card fraud, identity theft, or other crimes. Sensitive data deserves extra protection such as encryption at rest or in transit, as well as special precautions when exchanged with the browser.  How to mitigate:     12/17/2013 Encrypt all sensitive data at rest and in transit. Use standard algorithms with proper key management. Do not store sensitive data unnecessarily. Disable autocomplete and caching on pages that collect or display sensitive information. Mike Teterault, CISSP, CSSLP 12
  13. 13. A7: Missing Function Level Access Control  What it is:  Most web applications verify function level access rights before making that functionality visible in the UI. However, applications need to perform the same access control checks on the server when each function is accessed. If requests are not verified, attackers will be able to forge requests in order to access functionality without proper authorization.  What it looks like:    How to mitigate:  Implement a consistent and easy to analyze authorization module in your application. ○ Consider the process for managing entitlements to make sure it can be easily updated and audited. ○ The default state should be “deny all” with explicit authorizations.  Don’t rely on presentation logic alone to hide options from the user. ○ Authorization checks must also be implemented in the controller or business logic. 12/17/2013 Mike Teterault, CISSP, CSSLP 13
  14. 14. A8: Cross-Site Request Forgery  What it is:  A CSRF attack forces a logged-on victim’s browser to send a forged HTTP request, including the victim’s session cookie and any other automatically included authentication information, to a vulnerable web application. This allows the attacker to force the victim’s browser to generate requests the vulnerable application thinks are legitimate requests from the victim.  What it looks like:   Embedded link in malicious page: <img src=" " width="0" height="0" />  How to mitigate:  Include a unique token, individual to each user or session, in every page as a hidden field. ○ Verify that this token is returned with every request. If it is not, destroy the session and force the user to reauthenticate.  Require an explicit user authentication for high-value transactions. ○ This ensure the user is aware of the activity. 12/17/2013 Mike Teterault, CISSP, CSSLP 14
  15. 15. A9: Using Components with Known Vulnerabilities  What it is:  Components, such as libraries, frameworks, and other software modules, almost always run with full privileges. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications using components with known vulnerabilities may undermine application defenses and enable a range of possible attacks and impacts.  How to mitigate:  Don’t use external, third-part components. It’s not realistic, but it will work.  Identify all components and versions you are using. Keep up to date with both releases by the components maintainers and identified vulnerabilities on security mailing lists and databases. 12/17/2013 Mike Teterault, CISSP, CSSLP 15
  16. 16. A10: Unvalidated Redirects and Forwards  What it is:  Web applications frequently redirect and forward users to other pages and websites, sometimes using untrusted data to determine the destination pages. Without proper validation, attackers can redirect victims to phishing or malware sites, or use forwards to access unauthorized pages.  How to mitigate:  Don’t use redirects or forwards.  If you do have to, use tokens instead of the URL or a portion of the URL. This allows server-side code to translate the mapping to the target URL. 12/17/2013 Mike Teterault, CISSP, CSSLP 16
  17. 17. What now? First, are there any questions about the OWASP top ten vulnerabilities?  Web applications present a big target   Broad profile with rich data Where do you begin with your security efforts?  Enter: Threat Modeling!  12/17/2013 Mike Teterault, CISSP, CSSLP 17
  18. 18. What is Threat Modeling? A systematic approach for understanding, classifying, and assigning risk to threats and vulnerabilities  Security becomes what it should be: A cost/benefit analysis.  Based on two different classification schemes:   STRIDE ○ STRIDE classifies threat  DREAD ○ DREAD classifies risks 12/17/2013 Mike Teterault, CISSP, CSSLP 18
  19. 19. How do you start?  Identify your security objectives  All security can be characterized as being related to Confidentiality, Integrity, or Availability.  An objective can be tied to one or all of those characteristics  High Level Objective Categories      12/17/2013 Identity Financial Reputation Privacy and Regulatory Availability Guarantees Mike Teterault, CISSP, CSSLP 19
  20. 20. What does the application look like?  Application Overview  Understand the Components, Data Flows, and Trust Boundaries.  UML Use Case diagrams are handy for this.  Decompose the Application  Identify the features and modules with security impacts.  Understand: ○ How data enters the module. ○ How the module validates and processes the data. ○ Where the data flows. ○ How the data is stored. ○ What fundamental decisions and assumptions are made by the module.  Now that you know what the application looks like, you can classify its threats using the STRIDE model. 12/17/2013 Mike Teterault, CISSP, CSSLP 20
  21. 21. STRIDE – Characterizing Known Threats  Spoofing  Users cannot become another user or assume their attributes.  Tampering  Applications should never send internal data to users, and should always verify inputs before storing or processing it.  Repudiation  An application needs to be able to prove that authorized activities are initiated by authenticated users.  Information Disclosure  Applications should only store sensitive data if proper controls are in place.  Denial Of Service  Large, resource-intensive queries should only be accessible to properly authorized and authenticated users.  Elevation of Privileges  Users should only be able to access information and processing capabilities appropriate for their role in a system.  Each threat receives a DREAD score. 12/17/2013 Mike Teterault, CISSP, CSSLP 21
  22. 22. DREAD – Classifying, Quantifying, Comparing, and Prioritizing Risk  Each threat is scored on a 1-10 scale, added together, and divided by 5.  Damage  If a threat exploit occurs, how much damage will it cause?  Reproducibility  How easy is it to reproduce a threat exploit?  Exploitability  How difficult are the steps needed to exploit the threat?  Affected Users  How many users are affected if a threat is exploited?  Discoverability  How easy is it to discover the threat?  Often set to 10 by default, with the assumption that it will be discovered. 12/17/2013 Mike Teterault, CISSP, CSSLP 22
  23. 23. Next Steps   Analyze the DREAD score for each threat Understand the remediation for each threat, and what you need to do with the risk presented by each:  Acceptance – Not all security is “worth it” ○ You don’t spend $50,000 on security controls for a hot dog cart.  Avoidance – Just don’t do it ○ Not typically feasible in application development.  Limitation – Take steps to minimize risk ○ Most common risk management strategy. ○ Example: Disk drives may fail, so we maintain RAID and backups.  Transference – Let someone else take the risk ○ Outsource common functions that are not a core competency . ○ Purchasing insurance can be an option. 12/17/2013 Mike Teterault, CISSP, CSSLP 23
  24. 24. Questions / Comments / Resources    Twitter: @6502 Email: Resources:  OWASP – The Open Web Application Security Project ○  Threat Modeling, Frank Swiderski and Window Snyter, Microsoft Press, June 2004  Threat Modeling Web Applications, J.D. Meier, Alex Mackman, Blaine Wastell, Microsoft Press, May 2005  Mailing Lists and other resources: ○ Common Vulnerabilities and Exposures Database - ○ Microsoft Security Response Center ○ SANS – 12/17/2013 Mike Teterault, CISSP, CSSLP 24