If you work in cybersecurity, odds are you’re being pulled closer to the code.

Application Security (AppSec) was once a niche domain, but it is rapidly becoming a central focus in modern security teams. As attackers increasingly exploit software vulnerabilities and open source packages instead of going through the perimeter, more security professionals are being asked to understand and manage AppSec responsibilities, whether or not they come from a development background.

In fact, the shift is already happening:

• As of 2025, vulnerability exploitation has overtaken phishing as the top attack vector, and web applications are the most exploited pathways for breaches.
• Application security was among the top five fastest-growing skills requested in job postings in 2023–24.
• The Gartner Hype Cycle for Application Security 2024 emphasized that AppSec has moved from “emerging” to “mainstream,” driven by the ubiquity of DevSecOps, CI/CD pipelines, and supply chain risk.

In other words, whether you’re a seasoned security engineer, a compliance lead, or a cloud security architect, understanding AppSec is no longer optional.

Whether you’re adding AppSec to your existing responsibilities or building out a full AppSec program, this guide will give you the knowledge and tools to lead with confidence.

Understanding AppSec: Definition and Importance

Application Security (AppSec) is the discipline of  protecting software applications throughout their lifecycle, encompassing practices and tools to prevent vulnerabilities and address evolving threats. This includes designing, building, testing, and maintaining security features across the full software development lifecycle (SDLC). 

Unlike traditional cyber perimeter security (think firewalls, VPNs, or endpoint protection, etc), AppSec is focused on securing what’s inside the application: source code, configuration files, open source dependencies, APIs, AI models and AI-generated code, even business logic!

This distinction matters because applications are now the primary attack vector for cybercriminals. According to Verizon’s 2025 Data Breach Investigations Report, web applications remain the top target in confirmed data breaches. That makes AppSec not just a subset of cybersecurity, but a frontline defense.

The Evolution of DevSecOps and Shift Left

Historically, application security was treated as a final step, often just a manual penetration test run just before deployment. But as release cycles shortened (thanks to Agile and DevOps), this model broke down. Waiting until the end to fix critical issues wasn’t just risky, it was expensive and often too late. 

Over the past decade, the concept of “shift left”—embedding security checks early in the software development lifecycle—has gained broader acceptance. It relies on seamless integration into the tools developers already use so that vulnerabilities are addressed when code is written and reviewed rather than after release. Despite growing awareness, “shift left” is often an ideal state and can be extremely elusive for many businesses to implement in practice. As a result, integrating security across the software development lifecycle remains a work in progress, but it’s essential for catching issues early and continuously:

Modern AppSec now involves practices like threat modeling, design reviews, pentesting, bug bounty programs, SAST, DAST, SCA, and real-time monitoring—all automated where possible. Prioritizing application security is a key shift, with organizations integrating proactive measures early in the application development process. It’s proactive, continuous, and tailored to how software is actually built today.

The Core Components of Application Security

Every effective AppSec program is built on a foundation of proactive security measures woven throughout the software development lifecycle (SDLC). These measures aim to prevent vulnerabilities before they’re introduced, detect issues early, and respond swiftly when something goes wrong.

AppSec spans more than just tooling. It encompasses people, processes, and technology. At a high level, the core pillars include:

Application security tools—such as SAST, DAST, SCA, and IaC scanning—play a key role in automating detection and enforcement across these components. But technology alone isn’t enough.

To scale AppSec in modern environments, you need:

• Automation to handle complexity at velocity
  
• Context to separate real risks from noise
  
• Collaboration between security, engineering, and platform teams
  
  

Endor Labs supports this model by giving you deep visibility into OSS usage, code behavior, and exploitability—so you can embed security across people, processes, and pipelines.

Common Application Security Risks and Threats 

When it comes to application security, there’s no shortage of threats. Effective risk assessment is crucial for understanding and prioritizing application security threats. Let’s start with the foundational risks every team should understand, and the need to identify weaknesses in application design and implementation.

The OWASP Top 10: The Canon of App Vulnerabilities

The OWASP Top 10 is the most widely referenced list of critical application security risks. It’s updated every few years based on real-world data and expert consensus, and it serves as a baseline for secure software development.

As of the 2023 update (still current in 2025), the top vulnerabilities include:

1. Broken Access Control – Found in 94% of tested applications, this often leads to privilege escalation and data leaks.
2. Cryptographic Failures – Weak or misused encryption, leading to data exposure.
3. Injection – Including SQL, NoSQL, and OS command injection. Still dangerous despite being well known.
4. Insecure Design – A newer category reflecting flawed architectural decisions that create systemic risk.
5. Security Misconfiguration – Poorly configured cloud services, HTTP headers, or default settings.
6. Vulnerable and Outdated Components – Includes unpatched open source dependencies.
7. Identification and Authentication Failures – Weak or missing authentication mechanisms.
8. Software and Data Integrity Failures – Includes supply chain risks and insecure CI/CD practices.
9. Security Logging and Monitoring Failures – Impacts detection and incident response.
10. Server-Side Request Forgery (SSRF) – Increasingly common in cloud-native architectures.

Together, these issues can lead to data breaches, service downtime, and significant regulatory fines. And many of them are preventable with basic hygiene: secure defaults, dependency updates, and clear ownership.

Beyond the Basics: Emerging Threats to Watch

Modern applications face new categories of risk that aren’t always captured by static scans or legacy tools. Some of the most pressing threats include:

• Software Supply Chain Attacks: Threat actors are increasingly targeting upstream dependencies and open source maintainers. The SolarWinds and Log4Shell incidents made this risk impossible to ignore. Risks associated with third party components are especially significant, as organizations must carefully vet, monitor, and manage these external software dependencies to prevent vulnerabilities from entering their supply chain.
• Dependency Confusion: Attackers exploit naming collisions between private and public package registries, tricking build systems into pulling malicious code.
• Business Logic Attacks: These exploit how an app is intended to work, not necessarily how it was coded (e.g., abusing refund APIs or bypassing rate limits).‍
• Misconfigured Infrastructure-as-Code (IaC): Exposed secrets, excessive permissions, or insecure defaults in Terraform and Kubernetes configs.

3 Essential AppSec Security Controls

Protecting an application from threats isn’t about adding a single layer of defense, it’s about building security into every layer of the stack and every phase of design and development. That’s where security controls come in. Security controls help address security vulnerabilities at every layer by identifying, mitigating, and preventing risks throughout the application lifecycle.

In AppSec, these controls are generally grouped into three categories:

1. Preventive Controls

These are your front-line defenses: measures designed to stop vulnerabilities from being introduced in the first place and help protect applications from a wide range of threats. Common examples include:

• Access controls that enforce least privilege and prevent unauthorized actions.
• Authentication mechanisms such as biometric or multi-factor authentication and OAuth2 flows.
• Input validation to prevent injection attacks and malformed data.
• Secure development practices, like secure design reviews, threat modeling, automated scanning, and security champions and training..

Endor Labs supports preventive controls by enabling teams to establish governance policies for open source usage, enforce secure coding standards, and block high-risk packages at the pull request stage, before they become a liability.

2. Detective Controls

These controls help identify security issues once they’re present—either in code, dependencies, or deployed environments. They’re essential for early detection and fast response.

Examples include:

• Static Application Security Testing (SAST) to scan for code-level vulnerabilities.
• Software Composition Analysis (SCA) to find and evaluate vulnerabilities in third-party dependencies.
• Monitoring tools that detect anomalous behavior in production environments.

Endor Labs goes a step beyond traditional detective tools by analyzing whether a vulnerability is reachable and exploitable in your codebase. That means you can prioritize the alerts that actually matter, and avoid wasting time on theoretical risks.

Implementing these controls is fundamental to achieving software security, ensuring that applications are robustly protected against evolving threats.

3. Corrective Controls

Corrective controls kick in after a security issue has been identified—whether through detective tooling or real-world incidents. But it’s important to note: remediation isn’t the only option. Organizations generally have three responses to risk:

• Accept the risk (do nothing)
• Mitigate the risk (apply a compensating control)
• Remediate the risk (eliminate the root cause)
  

The right choice depends on your environment, risk tolerance, and business context. For instance, some teams may temporarily mitigate a vulnerability by adjusting a WAF rule or disabling a feature, while planning full remediation later. Others may decide to accept a low-impact issue due to cost or operational constraints.

Common corrective actions include:

• Patching or replacing vulnerable packages
• Revoking or rotating compromised secrets and keys
• Fixing access controls or misconfigured services
• Rolling back or reconfiguring faulty deployments
  

Where Endor Labs stands out is in enabling precision remediation. Rather than flooding developers with alerts, we show you exactly where the vulnerable function is called, what’s affected, and how to fix it—so you can act quickly and confidently, especially when response time matters.

Building Security into the SDLC

Security controls are most effective when integrated throughout the software development lifecycle. Integrating security practices at every stage of the software development life cycle is crucial to proactively address vulnerabilities and build secure applications. This means:

• Incorporating threat modeling and secure design reviews in planning stages.
• Integrating SAST and SCA tools into your CI pipelines during development.
• Performing DAST and security regression testing during QA.
• Enabling real-time monitoring and logging in production.
• Ensuring security considerations are addressed at each phase, including secure configurations, vulnerability assessment, and ongoing monitoring.

Endor Labs fits naturally into this model, plugging into your version control, CI/CD, and package management systems to provide continuous visibility and enforce secure policies at every step.

AppSec Tools and Technologies

Let’s be honest, keeping up with the alphabet soup of AppSec tooling can feel like a full-time job. Application security tools are essential for identifying and mitigating vulnerabilities throughout the software development lifecycle, helping teams detect issues early and maintain secure applications. SAST, DAST, IAST, SCA, RASP… each one solves a different piece of the security puzzle. But understanding how they work (and when to use them) is key to building a mature, effective AppSec program.

Here’s a breakdown of the most widely used tool types:

Types of Application Security Testing Tools

• Static Application Security Testing (SAST) Scans source code or bytecode at rest to identify security flaws like hardcoded secrets, input validation issues, or insecure cryptographic use. By detecting vulnerabilities that could expose sensitive information, SAST plays a key role in data protection and helps prevent data breaches. Great for early-stage detection, but can generate false positives.
• Dynamic Application Security Testing (DAST) Simulates attacks on a running application to detect exploitable vulnerabilities (like XSS or SQL injection). DAST helps strengthen data protection by uncovering weaknesses that attackers could exploit to access or compromise sensitive data. Doesn’t require source code but can miss deeper logic flaws.
• Interactive Application Security Testing (IAST) Combines elements of SAST and DAST by analyzing applications at runtime with instrumentation. Offers better accuracy, but can be more complex to deploy.
• Software Composition Analysis (SCA) Identifies vulnerabilities in third-party and open source components. Crucial for modern development where up to 90% of an app may come from reused code.
• Runtime Application Self-Protection (RASP) Embedded into applications to detect and prevent attacks in real time. Useful for high-risk, production environments, though adoption is still limited.

How to Choose the Right Tools

Not every team needs every tool. Choosing the right mix depends on your:

• Tech stack (e.g., language support, monolith vs. microservices)
• Development velocity (e.g., weekly releases vs. continuous deployment)
• Maturity level (e.g., just starting with AppSec vs. scaling a program)
• Team capacity (e.g., do developers fix issues directly, or hand off to security?)

A common mistake? Chasing “coverage” with overlapping tools that produce redundant alerts—slowing teams down instead of enabling them.

Implementing an Effective AppSec Program

So you’ve got the tools, you understand the risks, and your team is on board, now comes the harder part: putting it all together.

Security teams play a crucial role in implementing and managing application security programs, ensuring that best practices are followed throughout the development lifecycle.

Building an effective AppSec program isn’t just about scanning code or buying tools. It’s about creating a culture of security, where security professionals are key contributors in designing and overseeing security processes, backed by clear processes, measurable goals, and the right technical foundations. Here’s how to get there.

Build (and Evolve) the Right Team

There’s no one-size-fits-all model for an AppSec team. In early-stage organizations, it might be a single security engineer working alongside developers. In larger companies, it could be a full team embedded across business units.

Wherever you start, your AppSec team should:

• Partner closely with engineering, not just audit it
• Develop and evangelize secure coding standards
• Own security tooling and automation strategy
• Act as a liaison between development, DevOps, and compliance

Empower Security Champions

No AppSec team can scale alone. That’s why security champions (developers embedded in product teams who take ownership of secure development) are key.

A champion doesn’t need to be a security expert. They just need:

• Interest in AppSec and willingness to advocate best practices
  
• Access to training, resources, and tooling
  
• Support from leadership to influence team behavior
  

Creating a champion network helps shift security from “someone else’s job” to “part of how we build software here.”

Final Thought: Make AppSec Everyone’s Responsibility

The most effective AppSec programs don’t live in a silo. They’re collaborative, transparent, and aligned with business outcomes. When security becomes part of how your organization builds software (not a speed bump at the end) you reduce risk, improve quality, and earn user trust.

Want to see what that looks like in practice? Book a demo to learn how Endor Labs can help you implement a modern, scalable AppSec program that actually works.