Application security (AppSec) is the discipline of making software applications secure. It encompasses everything from secure design principles to testing techniques to incident response. Basically, it's how organizations systematically reduce the risk that their software can be exploited.
OWASP (Open Web Application Security Project) is a key resource for AppSec practitioners, providing guides, tools, and the well-known Top 10 list of critical web application security risks.
What AppSec Teams Do
AppSec teams typically operate across several areas. They define security requirements and standards that development teams should follow. They run or coordinate security testing methods like SAST, DAST, and penetration testing. They manage discovered vulnerabilities, and train developers on secure coding practices.
In some organizations, AppSec is deeply integrated with development teams. In others, it's a separate function that reviews finished products. The trend has been toward integration (DevSecOps), but organizational structures vary widely.
The Testing Arsenal
Most AppSec programs rely on a combination of testing approaches:
- Static analysis (SAST) scans source code.
- Dynamic testing (DAST) tests running applications.
- Penetration testing involves human experts attempting to find and exploit vulnerabilities.
- Software composition analysis checks dependencies for known issues.
Each approach has its strengths and limitations. Static analysis catches certain code patterns but misses runtime issues. Dynamic testing finds runtime issues but only in code paths it exercises. Penetration testing is thorough but expensive and infrequent.
Effective AppSec programs use multiple approaches to mitigate these limitations.
Evolving for AI
The rise of AI coding agents is changing how AppSec needs to operate. When code can be generated faster than traditional testing cycles, security needs to move earlier in the process, into the generation step itself.
ACSM represents this evolution: security that operates during code generation rather than after it. Traditional AppSec approaches remain valuable, but they're increasingly complemented by generation-time controls from tools like Corridor.