Pygoat - Learn django security the hard way - Djangocon US 2024

Code at: https://github.com/adarshdigievo/talks/tree/main/Djangocon%20US%2024%20-%20Pygoat%20-%20Django%20Security

Pygoat is an intentionally vulnerable Python Django application that can be used to learn to secure our Django apps. In this talk, we will attack a deployed Pygoat application, identify the underlying security issues in our code, and then secure it. We will learn about common security vulnerabilities (OWASP Top 10) in Django apps and how to fix them so that we can keep our applications safe from attackers.

Transcript

1. PyGoat Learn Django security the hard way Adarsh Divakaran Co-Founder and Lead Consultant @ Digievo Labs
2. Web Application Security Web application security encompasses a range of measures, technologies, or approaches aimed at safeguarding web servers, web applications, and web services, including APIs, against potential attacks from online threats.
3. Web Application Security • Based on an analysis of 14 million websites, SiteLock reports that websites currently experience an average of 172 attacks every day • Cyberattacks cost small and medium-Sized Businesses $25k annually on average • The volume of threats are doubling year over year Source: https://www.sitelock.com/resources/security-report
4. Web Application Security For the businesses, these attacks lead to: • Loss of credibility • Financial loss • Compromise of user data
6. Ensuring Web Application Security • Lots of resources are available on building Web applications • Relatively less guidance and resources for building Secure Web Applications. • Security is often learned the hard way.
7. OWASP The Open Worldwide Application Security Project (OWASP) is an online community that produces freely-available articles, methodologies, documentation, tools, and technologies in the field of web application security. OWASP provides tools and resources for security researchers as well as developers to test and fortify their applications.
8. OWASP Top 10 The OWASP Top 10 is a regularly-updated report outlining security concerns for web application security, focusing on the 10 most critical risks. The report is put together by a team of security experts from all over the world. Current version: 2021 https://owasp.org/www-project-top-ten/
10. The Pygoat Project Pygoat is an intentionally vulnerable Python Django application that can be used to learn to secure our Django apps. Pygoat contains (intentionally insecure) labs to learn about and exploit the OWASP top 10 vulnerabilities.
11. A3: Injection Injection happens when an attacker sneaks in untrusted data and tricks the interpreter into doing things it shouldn't, like running unintended commands or accessing unauthorized data. Eg: SQL, NoSQL, OS command, Object Relational Mapping (ORM) injection
12. Pygoat Lab 1 Mission: Get unauthorized access as admin
13. Security Testing Methodology A security researcher will: • Perform enumeration against the target - Identify the tech stack, various operations and find points of attack. • They will then proceed with testing the web application functionalities (against multiple vulnerabilities) to uncover security bugs - using automated or manual tools.
14. Our Methodology • We will look into various Pygoat labs • Each lab has an objective • Since Pygoat source code is available to us, we can easily spot the security issues and attack each of the labs without much trial and error.
15. Demo
16. Pygoat Lab 1 SELECT * FROM introduction_login WHERE user='"+name+"'AND password='"+password+"'" When name is “john” and password is “pass1”, it becomes: SELECT * FROM introduction_login WHERE user='john' AND password='pass1'
17. Pygoat Lab 1 SELECT * FROM introduction_login WHERE user='"+name+"'AND password='"+password+"'" What if we enter password as: any' OR '1'='1 SELECT * FROM introduction_login WHERE user='john' AND password='any' OR '1'='1'
19. Vulnerable Code
20. Pygoat Lab 2 Mission: Run shell commands on the server
21. Demo
25. Mitigation • The preferred option is to use a safe API, which avoids using the interpreter entirely, provides a parameterized interface, or migrate to Object Relational Mapping Tools (ORMs). • Use positive server-side input validation. This is not a complete defense as many applications require special characters. • For any residual dynamic queries, escape special characters using the specific escape syntax for that interpreter.
26. Mitigation Django Specific: • Django ORM usage removes SQLi vulnerability. Raw queries should be avoided if possible. • Django templates has built-in protection against (most) XSS attacks, another injection vulnerability. Python specific: • Do not allow command/code execution (os.system, subprocess or eval) using user supplied inputs.
27. A5: Security Misconfiguration The application might be vulnerable if the application is: • Missing appropriate security hardening across any part of the application stack or improperly configured permissions on cloud services. • Unnecessary features are enabled or installed (e.g., unnecessary ports, services, pages, accounts, or privileges). • Default accounts and their passwords are still enabled and unchanged. • Error handling reveals stack traces or other overly informative error messages to users.
28. Pygoat Lab 1 Mission: Get a secret key that is only visible to the admin.
29. Demo
34. Mitigation This case is an example of Security through obscurity. • Raw inputs from front end should not be trusted. • As seen in the lab if access controls are enforced using predictable, front-end supplied values, there is a risk of attack. Cookies/token values should be truly random and unpredictable.
35. In Real-World Facebook Bug: Delete any Facebook page [source] Found by Arun Suresh Kumar (2016) • The misconfiguration vulnerability could have allowed an attacker to delete any facebook page. • An attacker could intercept a deletion request (for their own page) sent from the front-end and swap the id to any page id to delete it. • The users’ permission to manage the page was not checked in the backend.
36. Pygoat Lab 2 Mission: Get a sensitive env variable stored in the application.
37. Demo
41. Mitigation Django debug mode was enabled. This can lead to tracebacks, error messages and env variables being displayed to users. In a publicly accessible environment, Debug mode should be disabled.
42. Security Misconfiguration - Prevention • A repeatable hardening process makes it fast and easy to deploy another environment that is appropriately locked down. This process should be automated to minimize the effort required to set up a new secure environment. • Remove or do not install unused features and frameworks. • A task to review and update the configurations appropriate to all security notes, updates, and patches as part of the patch management process. • Review cloud storage permissions (e.g., S3 bucket permissions). • An automated process to verify the effectiveness of the configurations and settings in all environments.
43. A6: Vulnerable and Outdated Components The application might be vulnerable: • If the software used is vulnerable, unsupported, or out of date. This includes the OS, web/application server, database management system (DBMS), applications, APIs and all components, runtime environments, and libraries. • If you do not scan for vulnerabilities regularly and subscribe to security bulletins related to the components you use.
44. Pygoat Lab - Objective Mission: Execute code on the server (RCE) using an outdated dependency.
45. Demo
46. Pygoat Lab - Vulnerable Components This lab helps us to understand why components with known vulnerabilities can be a serious issue. The user on accessing the lab is provided with a feature to convert yaml files into json objects. A yaml file needs to be chosen and uploaded to get the json data. The app uses pyyaml 5.1 which is vulnerable to code execution.
47. Pygoat Lab We can craft a yaml as shown below to execute code on the server
51. Mitigation • Remove unused dependencies, unnecessary features, components, files, and documentation. • Continuously inventory the versions of both client-side and server-side components (e.g., frameworks, libraries) and their dependencies using tools like versions, OWASP Dependency Check, retire.js, etc. Continuously monitor sources like Common Vulnerability and Exposures (CVE) and National Vulnerability Database (NVD) for vulnerabilities in the components. • Only obtain components from official sources over secure links. Prefer signed packages to reduce the chance of including a modified, malicious component (See A08:2021-Software and Data Integrity Failures).
52. A7: Identification and Authentication Failures There are times when the way applications handle passwords and user logins is done incorrectly. This can let attackers get access to passwords, keys, or tokens, or take advantage of other mistakes in how the app works to pretend to be someone else, either for a little while or forever.
53. Pygoat Lab - Objective Mission: The aim of this lab is to login as admin.
54. Demo
55. Pygoat Lab We need to exploit the lack of rate limiting feature in the otp verification flow. You can see that the otp is only of 3 digit and the application doesn’t have any captcha (To disallow any automated scripts or bots) or any restrictions on the number of tries for the otp.
62. Mitigation • Where possible, implement multi-factor authentication to prevent automated credential stuffing, brute force, and stolen credential reuse attacks. • Do not ship or deploy with any default credentials, particularly for admin users. • Implement weak password checks, such as testing new or changed passwords against the top 10,000 worst passwords list. • Limit or increasingly delay failed login attempts, but be careful not to create a denial of service scenario. Log all failures and alert administrators when credential stuffing, brute force, or other attacks are detected.
63. In Real World Facebook Password Reset (2016) Source: Getting $15,000 bounty for a bug that let me hack into any of Facebook’s 2 billion accounts - Anand Prakash • Facebook used 6 digits password recovery codes • Brute force was blocked on Facebook.com root domain after a few attempts • But there was no limits on the number of attempts on beta.facebook.com domain.
64. References OWASP Top 10: https://owasp.org/Top10/ Django Security Doc: https://docs.djangoproject.com/en/5.1/topics/security/ Pygoat Project and Demos: https://github.com/adeyosemanputra/pygoat https://github.com/adarshdigievo/pygoat [Fork] https://www.youtube.com/watch?v=k_C5bNF1VGs
65. Learning resources Hacksplaining: https://www.hacksplaining.com/owasp Web Security Academy: https://portswigger.net/web-security Owasp Cheatsheets: https://cheatsheetseries.owasp.org/IndexTopTen.html
66. Thank You linkhq.co/adarsh Get the talk materials & connect with me
67. Bonus Slides Remaining OWASP top 10 vulnerabilities
68. A1 Broken Access Control Access control, sometimes called authorization, is how a web application grants access to content and functions to some users and not others. These checks are performed after authentication, and govern what ‘authorized’ users are allowed to do.
69. PyGoat Lab 1
73. Vulnerable Code
74. Mitigation • Except for public resources, deny by default. • Implement access control mechanisms once and re-use them throughout the application. • Rate limit API and controller access to minimize the harm from automated attack tooling. • Stateful session identifiers should be invalidated on the server after logout. Stateless JWT tokens should rather be short-lived so that the window of opportunity for an attacker is minimized. For longer lived JWTs it's highly recommended to follow the OAuth standards to revoke access.
75. A2 Cryptographic Failures Cryptographic failure is the root cause of Sensitive Data Exposure. Enumerations (CWEs) included are CWE-259: Use of Hard-coded Password, CWE-327: Broken or Risky Crypto Algorithm, and CWE-331 Insufficient Entropy.
79. Mitigation • Classify data processed, stored, or transmitted by an application. Identify which data is sensitive according to privacy laws, regulatory requirements, or business needs. • Don't store sensitive data unnecessarily. Discard it as soon as possible or use PCI DSS compliant tokenization or even truncation. Data that is not retained cannot be stolen. • Make sure to encrypt all sensitive data at rest. • Ensure up-to-date and strong standard algorithms, protocols, and keys are in place; use proper key management. • Encrypt all data in transit with secure protocols such as TLS with forward secrecy (FS) ciphers, cipher prioritization by the server, and secure parameters. Enforce encryption using directives like HTTP Strict Transport Security (HSTS). • Disable caching for response that contain sensitive data.
80. A4: Insecure Design Insecure design is a type of flaw that can sit in the background of everything you do. This vulnerability relates to how you as a developer design your programs, architect solutions, and employ security practices such as threat modeling
81. Pygoat lab objective
82. This website is giving everyone free tickets ( upto 5 per person ). And the movie will be public when all the tickets will be sold. The ticket generating system is inherently secure, limiting users to obtain a maximum of 5 free tickets. However, a significant design flaw exists – multiple accounts can be created to acquire an unlimited number of tickets. For instance, in this specific scenario where 60 tickets are required, one could easily exploit the system by creating just 12 accounts, claiming 5 tickets from each.
84. Mitigation • Establish and use a secure development lifecycle with AppSec professionals to help evaluate and design security and privacy-related controls • Establish and use a library of secure design patterns or paved road ready to use components • Use threat modeling for critical authentication, access control, business logic, and key flows • Integrate security language and controls into user stories • Integrate plausibility checks at each tier of your application (from frontend to backend)
85. Mitigation • Write unit and integration tests to validate that all critical flows are resistant to the threat model. Compile use-cases and misuse-cases for each tier of your application. • Segregate tier layers on the system and network layers depending on the exposure and protection needs • Segregate tenants robustly by design throughout all tiers • Limit resource consumption by user or service
86. A8 Software and Data Integrity Failures Software and data integrity failures relate to code and infrastructure that does not protect against integrity violations. An example of this is where an application relies upon plugins, libraries, or modules from untrusted sources, repositories, and content delivery networks (CDNs). Eg: Insecure Deserialization Applications and APIs will be vulnerable if they deserialize hostile or tampered objects supplied by an attacker. This can result in two primary types of attacks: • Object and data structure related attacks where the attacker modifies application logic or achieves arbitrary remote code execution if there are classes available to the application that can change behavior during or after deserialization. • Typical data tampering attacks such as access-control-related attacks where existing data structures are used but the content is changed.
87. Pygoat Lab
90. Vulnerability Page is vulnerable to XSS. Name is directly printed from the url param. If we specify name value as: user+<script>document.getElementById("download_link").setAttri bute("href"%2C"%2Fstatic%2Ffake.txt")%3B<%2Fscript>user+<scri pt>document.getElementById("download_link").setAttribute("href" %2C"%2Fstatic%2Ffake.txt")%3B<%2Fscript> The download url is modified and user may download an arbitrary file by trusting the domain
92. Mitigation For the demonstrated vulnerability, XSS is used to redirect user to a fake file. As a user we should always cross-check signatures for verification of Data Integrity. Checksums should be provided for downloads so that it can be cross checked from user end.
93. Mitigation • Use digital signatures or similar mechanisms to verify the software or data is from the expected source and has not been altered. • Ensure libraries and dependencies, are consuming trusted repositories. If you have a higher risk profile, consider hosting an internal known-good repository that's vetted. • Ensure that a software supply chain security tool, such as OWASP Dependency Check or OWASP CycloneDX, is used to verify that components do not contain known vulnerabilities • Ensure that your CI/CD pipeline has proper segregation, configuration, and access control to ensure the integrity of the code flowing through the build and deploy processes. • Ensure that unsigned or unencrypted serialized data is not sent to untrusted clients without some form of integrity check or digital signature to detect tampering or replay of the serialized data
94. A09: Security Logging and Monitoring Failures This category is to help detect, escalate, and respond to active breaches. Without logging and monitoring, breaches cannot be detected. Insufficient logging, detection, monitoring, and active response occurs any time: • Auditable events, such as logins, failed logins, and high-value transactions, are not logged. • Warnings and errors generate no, inadequate, or unclear log messages. • Logs of applications and APIs are not monitored for suspicious activity. • Appropriate alerting thresholds and response escalation processes are not in place or effective. • Penetration testing and scans by dynamic application security testing (DAST) tools (such as OWASP ZAP) do not trigger alerts. • The application cannot detect, escalate, or alert for active attacks in real-time or near real-time.
95. Pygoat Lab
99. Mitigation Ensure all login, access control, and server-side input validation failures can be logged with sufficient user context to identify suspicious or malicious accounts and held for enough time to allow delayed forensic analysis. Ensure that logs are generated in a format that log management solutions can easily consume. Ensure log data is encoded correctly to prevent injections or attacks on the logging or monitoring systems. Ensure high-value transactions have an audit trail with integrity controls to prevent tampering or deletion, such as append-only database tables or similar. DevSecOps teams should establish effective monitoring and alerting such that suspicious activities are detected and responded to quickly.
100. A10: Server Side Request Forgery (SSRF) • SSRF flaws occur whenever a web application is fetching a remote resource without validating the user-supplied URL. It allows an attacker to coerce the application to send a crafted request to an unexpected destination. Sample usages for remote url fetching: DNS Checkers, URL previews on social media • Common attacks: Attacks on internal services/files, Attack on external URLs (DoS)
101. Pygoat - SSRF Lab
106. Vulnerable Code
109. Mitigation From Application layer: • Sanitize and validate all client-supplied input data • Enforce the URL schema, port, and destination with a positive allow list • Do not send raw responses to clients
110. Fixed code
111. Fixed code
112. Thank You linkhq.co/adarsh Get the talk materials & connect with me