As security researchers and professionals, we often find ourselves searching through countless resources, documentation, and references while working on projects or investigating vulnerabilities. Having a well-organized collection of links and resources can be invaluable for both learning and day-to-day work. This is exactly what appsec.fyi provides - a thoughtfully curated collection of application security resources that serves as a go-to reference point for security professionals.

What is AppSec.fyi?

AppSec.fyi describes itself as “a somewhat curated list of links to various topics in appsec. Mostly, but not always related to application security.” This humble description understates the value of what the site offers. At its core, it’s a centralized hub that organizes security knowledge across multiple domains, making it easy to find authoritative sources and reference materials for common vulnerabilities and security topics.

The site takes a simple but effective approach - each major vulnerability class or topic gets its own dedicated page with curated links to high-quality resources, primarily from OWASP but also including other authoritative sources like Wikipedia, vendor documentation, and security tools.

Coverage and Organization

The site covers a comprehensive range of application security topics, organized as a clean landing page with links to detailed topic pages. The main categories include:

Core Vulnerability Classes

  • Insecure Direct Object Reference (IDOR) - Links to OWASP prevention cheat sheets
  • Cross-Site Scripting (XSS) - References to OWASP attack documentation
  • SQL Injection - Coverage of database injection vulnerabilities
  • XML External Entity Processing (XXE) - Details on XML-based attacks
  • Server-Side Request Forgery (SSRF) - Resources on server-side abuse
  • Cross-Site Request Forgery (CSRF) - State-changing attack vectors
  • Remote Code Execution (RCE) - Arbitrary code execution references

Security Domains and Practices

  • AI Security - Protecting AI systems from threats like data poisoning and model inversion
  • Open-Source Intelligence (OSINT) - Publicly available intelligence gathering
  • Bug Bounty Related - Resources for bug bounty programs and researchers
  • Reconnaissance - Information gathering techniques
  • Fuzzing - Automated testing methodologies

Tools and Technologies

  • Burp Suite - The leading web application testing platform from PortSwigger
  • Python - Programming resources (with a note about being a Python convert)
  • GraphQL - API query language security considerations

Additional Resources

  • Talks - A dedicated page cataloging security presentations and talks with dates, links, and excerpts
  • The talks page includes content from sources like Speaker Deck, featuring presentations on topics ranging from OWASP projects to security scaling guides

What Makes It Valuable

Several aspects make appsec.fyi particularly useful:

Quality Over Quantity: Rather than overwhelming visitors with hundreds of links, the site focuses on curating high-quality, authoritative resources. Most entries link directly to OWASP documentation, which is widely recognized as the gold standard for web application security guidance.

Practical Organization: Topics are organized in a way that mirrors how security professionals actually work. Whether you’re investigating a potential SSRF vulnerability or need to refresh your knowledge on XSS variants, you can quickly navigate to the relevant section.

Personal Touch: The creator, Carl Sampson, brings personal context to the collection. The Python section notes “Not really security related, but I’m a recent Python convert” - showing that the site reflects genuine use and interest rather than just algorithmic aggregation.

Easy Navigation: The simple, clean design makes it easy to scan topics and find what you need. The landing page provides brief descriptions of each topic, while dedicated pages offer more detailed resource collections.

Regularly Updated: The talks section shows dates for when content was added, and the inclusion of recent presentations suggests the site is actively maintained.

Use Cases

AppSec.fyi serves several practical purposes for security professionals:

Learning Path: For those new to application security, the site provides a structured way to explore different vulnerability classes, starting with authoritative resources rather than random blog posts or outdated documentation.

Quick Reference: During security assessments or code reviews, having quick access to OWASP cheat sheets and attack documentation can be invaluable for confirming attack vectors or mitigation strategies.

Training Resource: Security teams can use the site as a baseline reading list for new team members or for ongoing security education programs.

Research Starting Point: When investigating a new vulnerability class or attack technique, the curated links provide a solid foundation before diving into more specialized resources.

The Human Element

What sets appsec.fyi apart from automated link aggregators is its human curation. The site reflects the judgment and experience of someone actively working in application security, choosing resources that are actually useful rather than just highly ranked in search results. The inclusion of categories like “Talks” with hand-picked presentations shows the kind of contextual knowledge that comes from being engaged with the security community.

Final Thoughts

In an era of information overload, having a trusted, curated collection of security resources is increasingly valuable. AppSec.fyi fills this niche effectively by maintaining a focused collection of high-quality links across the major application security domains. Whether you’re a seasoned security professional looking for quick references or someone building their security knowledge, the site offers a practical, well-organized starting point.

For those interested in exploring it further, appsec.fyi is maintained by Carl Sampson and represents the kind of community contribution that strengthens the security profession as a whole. It’s a reminder that sometimes the most useful tools are the simplest ones - a well-curated list of links, maintained by someone who knows what security professionals actually need.

Visit: https://appsec.fyi