Requirement
Essential Cybersecurity Controls (ECC – 2 : 2024) - Control - 2-15-3 – The cybersecurity requirements for external web applications must include at least the following:
Understanding the Requirement
This control requires organizations to define and apply minimum cybersecurity requirements for any externally facing web application. The control's sub-objectives (2-15-3-1 through 2-15-3-5) signal that the policy must cover multiple technical and operational areas such as secure configuration, authentication and session management, input validation and secure coding, vulnerability and patch management, and logging/monitoring. As part of implementing Essential Cybersecurity Controls (ECC – 2 : 2024), SMBs should treat external web applications as a frontline risk area and enforce a consistent set of controls from development through production and operations.
Technical Implementation
- Inventory and ownership: Maintain an authoritative inventory of all external web applications (including microsites, APIs, and third-party-hosted apps). Assign an application owner and document runtime environment, dependencies, third-party libraries, and hosting provider. Use a simple spreadsheet or a lightweight asset-management tool and update it as part of change control.
- Secure transport and configuration: Enforce TLS 1.2+ with strong cipher suites and HSTS. Configure secure HTTP headers (Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy) and disable unnecessary services. Harden server and container images with a baseline configuration and automate configuration checks in CI/CD.
- Authentication, authorization, and session controls: Require multi-factor authentication for administrative access and privileged user paths; use strong password rules and rate limiting for login endpoints. Implement role-based access controls (RBAC) and ensure session timeouts, secure cookies (HttpOnly, Secure, SameSite), and token expiration policies are in place.
- Secure development and input handling: Apply secure coding practices: parameterized queries/ORMs to avoid SQL injection, output encoding to prevent XSS, input validation and schema checks for APIs, and CSRF protection. Integrate SAST and dependency scanning into CI pipelines and run DAST scans against staging environments before production deployment.
- Vulnerability management and testing: Schedule automated dependency scanning (SCA) and patch management with defined SLAs (e.g., critical libraries patched within 7 days, high within 30). Perform authenticated vulnerability scans monthly and arrange an external penetration test annually or after significant changes. Track remediation with ticketing and closure verification.
- Logging, monitoring, and incident readiness: Centralize web application logs (access, error, auth events) to a log collector or cloud logging service, retain logs for an agreed period, and create alerting rules for anomalous patterns (repeated failed logins, high error rates, suspicious payloads). Maintain a lightweight incident response playbook for web application incidents and periodically run tabletop exercises.
Example in a Small or Medium Business
A small e-commerce company with a single externally facing web store begins by listing the application, its API endpoints, the hosting provider, and used third-party modules in a shared asset register. The CTO assigns an owner and introduces a baseline configuration template that enforces TLS 1.3, HSTS, and secure headers on the webserver. Developers add OWASP controls to their CI pipeline: static code scans on pull requests, automated dependency checks (Dependabot or similar), and a DAST run against the staging environment nightly. For authentication, the company enables multi-factor authentication for the admin portal and implements session timeouts and secure cookies for customers. They subscribe to a managed WAF from their cloud provider and tune it using a 30-day monitoring window to reduce false positives, while forwarding application logs to a centralized logging service where simple alerts notify the operations lead of repeated login failures or sudden spikes in 500 errors. Finally, the business schedules quarterly vulnerability scans and an annual external penetration test; remediation tickets are assigned with target SLAs and verified by the application owner before closure.
Summary
By combining a clear policy (inventory, ownership, patch timelines, testing cadence) with specific technical controls (TLS and headers, secure coding, authentication controls, automated scanning, WAF, and centralized logging), SMBs can meet the requirement for securing external web applications. These measures reduce common attack surfaces, speed detection and response, and create repeatable processes so that new and changed applications are brought under the same protective baseline.
