Application security (AppSec) represents one of today's greatest opportunities and challenges for development and security teams. The application security market is on track to double in value by 2029, driven by digital transformation demands. Application security risks pose one of the biggest barriers to digital transformation, with organizations resolving less than 70% of serious findings, highlighting a big disconnect between testing and a process for addressing security issues. According to The State of Pentesting Report 2025, of remediated findings, these average only 37 days to fix, which is faster than ever before, but still creating backlogs for organizations.
This makes AppSec a high priority for developers and security teams responsible for protecting company data, safeguarding business continuity, and ensuring customer trust. To assist IT professionals tasked with application security, here's a detailed look at what AppSec is, why it's important, how it's done, and where to tap into AppSec expertise.
Application security is the branch of cybersecurity that protects the software application layer of digital networks. It complements cybersecurity specializations that protect other layers, such as network, data, and physical security. It includes security for web apps, cloud apps, mobile apps, and APIs.
AppSec protects application layers from the technical and business impact of risks such as broken access control, cryptographic failures, and malicious code injection. It mitigates these threats using techniques such as authentication, encryption, and validity checks. To implement these defenses, AppSec deploys tools such as Static Application Security Testing (SAST), Dynamic Application Security Testing (DAST), Interactive Application Security Testing (IAST), and Run-time Application Security Protection (RASP). Testing methodologies such as penetration testing (pentesting) and red teaming evaluate the effectiveness of security measures.
Conceptually, several key distinctions play a pivotal role in application security methodology:
Authentication and authorization refer to fundamental identity access management (IAM) procedures for limiting use of accounts:
Essentially, authentication confirms who a user is, while authorization controls what they can access. For example, a bank customer who presents valid credentials to their provider's app will be authenticated and consequently authorized to access their own account information, but not authorized to access other customers' information or administrative functionality.
Vulnerabilities, threats, and risk distinguish three related phases in potential application security breaches, corresponding to different types of security reports and alerts:
For example, a human resources app's URL structure might contain a flaw in access control (vulnerability) which enables attackers to edit URLs to access other users' accounts (threat) and steal account data (risk).
AppSec distinguishes security testing from quality assurance testing as two different types of preventive checks:
For example, a security test on an ecommerce app might verify whether authentication procedures are stopping hackers from accessing customer accounts, while a QA test might confirm that the checkout cart works correctly.
Application security serves many vital functions for businesses, including:
The benefits of application security and the risks of neglecting AppSec make safeguarding apps critical for any effective security posture.
The process of implementing application security can be broken into eight essential steps:
The AppSec process begins with identifying potential vulnerabilities through threat modeling. This requires analyzing the app from an attacker's perspective. Map potential attack surfaces by reviewing the flow of data and commands through the app, all data used by the app, and all code protecting data and functional flow. This analysis can be segmented by user roles and privileges. Once attack surfaces have been mapped, they can be developed into threat models by correlating attack points with potential attacker types, systems being targeted, system vulnerabilities, and attack methods and techniques. To assist with the threat modeling process, teams can use established frameworks such as MITRE ATT&CK or Microsoft's STRIDE.
Once vulnerabilities have been identified, they can be prioritized in terms of risk. This helps teams focus resources on the most pressing threats. Risks can be itemized and ranked in terms of criteria such as business impact, asset criticality, threat intelligence insights, or standardized scoring systems for ranking severity such as the Common Vulnerability Scoring System (CVSS).
Conducting risk assessment enables teams to develop strategic mitigation plans. Resources such as the Open Web Application Security Project (OWASP) Top Ten assist mitigation planning by recommending preventive measures and fixes corresponding to common risk categories.
Designers and developers can reduce security incidents by building mitigations into apps early in their lifecycle. Threat modeling and mitigation planning provides a foundation for secure design. Developers can promote app security by using secure coding, libraries, and development frameworks. Regulatory requirements increasingly obligate teams to implement a security-first mindset throughout the software lifecycle.
Secure code reviews serve as a preliminary check on the effectiveness of secure design and development efforts. A good code review should investigate specific vulnerabilities and generate concrete reports and recommendations. The code review process may include both manual peer review and automated review using tools such as SAST, DAST, and IAST.
Security tests reinforce the effectiveness of code reviews by identifying overlooked vulnerabilities. Testing methods include penetration testing, where security teams conduct prearranged vulnerability probes, and red teaming, where teams simulate attacks without advance warning.
Results of security tests uncover lingering vulnerabilities that require remediation. Implementing these fixes is the next stage of the AppSec process prior to live app deployment.
Once applications are deployed, ongoing monitoring maintains security against ongoing threats. Automated deployment pipelines help maintain security during the transition from development to deployment by enforcing version control, verifying compiled code, providing realistic development environments, and using simulated production environments and canary tokens to facilitate quick version rollbacks. Security logs, alerts, and update and patching procedures help keep live deployments secure.
AppSec processes protect applications against leading vulnerabilities such as:
OWASP helps monitor threat trends and recommend remediations for common vulnerabilities.
The variety of possible defenses against common application attack methods are numerous, but for a convenient overview, they can be grouped into a few major categories:
Resources such as OWASP provide detailed recommendations for which techniques to use against specific vulnerabilities.
To implement AppSec techniques and ensure their effectiveness, security teams employ a variety of automated tools. These include:
These automated tools work in conjunction with manual methods to support AppSec strategies.
To evaluate the effectiveness of AppSec measures, security teams use a variety of testing methods to probe defenses. Two of the most important testing methods are:
Pentesting typically has a broad scope based on defined criteria to identify a range of potential vulnerabilities, whereas red teaming simulates an actual attack targeting vulnerabilities identified by the attack team. Together, pentesting and red teaming provide comprehensive insight into app vulnerabilities.
Pentesting provides one of the most effective ways to ensure app security, and several major regulatory frameworks now require it. However, running your own pentests can be challenging, while working with external pentesters often requires months to plan and schedule tests.
Fortunately, The Cobalt Penetration Testing as a Service (PTaaS) Platform makes it easy for you to schedule tests with experienced pentesters within as little as 24 hours. Our elite team of vetted experts works with your team to plan customized tests based on your criteria, inform you of results in real-time, and implement remediations through integration with your existing tools. Check out our pentesting services to book a meeting with us, get a demo, or learn more about how Cobalt can help you secure your applications to protect your data and safeguard your business.