Free Secure Software Development Lifecycle (SSDLC) Policy Builder

1. Purpose

This policy establishes requirements for integrating security controls throughout the software development lifecycle to build secure, reliable, and resilient software systems. The goal is to identify and remediate security vulnerabilities early in development, implement secure coding practices, automate security testing, reduce security debt, and meet SOC 2 compliance requirements for secure software development.

2. Scope

Applies to all software development activities including new product development, feature enhancements, bug fixes, infrastructure-as-code, API development, mobile applications, web applications, and microservices. Covers all phases of the software development lifecycle from requirements and design through coding, testing, deployment, and maintenance. Includes all developers, engineers, product managers, QA testers, and DevOps personnel involved in software delivery.

3. Roles and Responsibilities

• Chief Technology Officer (CTO) – owns this policy, ensures resources allocated for secure development practices, champions security-first engineering culture
• Security Champion / AppSec Lead – provides security guidance to development teams, conducts security reviews, maintains security tooling, tracks vulnerability remediation
• Engineering Managers – ensure teams follow SSDLC requirements, allocate time for security activities, review and approve security findings
• Software Engineers / Developers – write secure code following best practices, participate in code reviews, remediate security findings, complete security training
• QA / Test Engineers – perform security testing, validate security controls, verify vulnerability fixes
• DevOps / SRE Team – implement security automation in CI/CD pipelines, maintain secure deployment infrastructure, monitor production security
• Product Managers – include security requirements in product specifications, prioritize security work, balance features with security needs

4. Secure Development Principles

Core Security Principles

• Security by Design – security considerations integrated from initial design phase, not added as afterthought
• Defense in Depth – multiple layers of security controls to protect against threats
• Principle of Least Privilege – systems and users granted minimum permissions necessary
• Secure by Default – default configurations are secure; users must opt-in to less secure options
• Fail Securely – systems fail in secure state without exposing sensitive data or functionality
• Separation of Duties – critical operations require multiple parties to prevent single point of compromise
• Complete Mediation – every access to resources is checked for authorization
• Open Design – security does not rely on secrecy of implementation (no security through obscurity)

Shift-Left Security

Organization embraces shift-left security approach:

• Identify security issues as early as possible in development lifecycle
• Earlier detection = lower cost and faster remediation
• Empower developers with security knowledge and tools
• Automate security checks in developer workflow
• Provide rapid feedback on security issues

5. Requirements and Design Phase

Security Requirements Definition

Security requirements documented for all new projects and major features:

• Authentication Requirements: How will users authenticate? (passwords, SSO, MFA, API keys)
• Authorization Requirements: What access controls are needed? (RBAC, ABAC, resource-level permissions)
• Data Protection Requirements: What data needs encryption? What PII is processed? What data retention is required?
• Input Validation Requirements: What inputs need validation? What character sets are allowed?
• Logging and Monitoring Requirements: What security events must be logged? What alerts are needed?
• Third-Party Dependencies: What external libraries or services will be used? Have they been security reviewed?
• Compliance Requirements: What regulations apply? (SOC 2, GDPR, HIPAA, PCI-DSS)

Threat Modeling

Threat modeling conducted for major features and new product development:

• Identify assets (data, functionality, infrastructure)
• Identify threats (STRIDE model: Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege)
• Identify attack vectors and entry points
• Assess risk severity for each threat
• Define security controls to mitigate threats
• Document threat model in design documentation
• Review threat model with Security Champion

Secure Architecture Review

Architecture design reviewed for security considerations:

• Network segmentation and isolation
• Authentication and authorization flows
• Data flow and encryption at rest/in transit
• API security and rate limiting
• Secrets management approach
• Logging and monitoring architecture
• Disaster recovery and business continuity

6. Development Phase

Secure Coding Standards

Developers follow secure coding standards to prevent common vulnerabilities:

Input Validation and Output Encoding

• Validate all user inputs on server-side (never trust client-side validation alone)
• Use allowlists rather than blocklists for input validation
• Encode output to prevent injection attacks (XSS, SQL injection, command injection)
• Use parameterized queries or ORM for database access (never concatenate SQL)
• Sanitize user input before rendering in HTML, JavaScript, or other contexts

Authentication and Session Management

• Never store passwords in plain text; use strong hashing (bcrypt, Argon2, PBKDF2)
• Implement secure session management (secure cookies, HttpOnly, SameSite flags)
• Use cryptographically secure random values for session tokens
• Implement session timeout and idle timeout
• Require re-authentication for sensitive operations
• Implement rate limiting to prevent brute force attacks

Authorization and Access Control

• Implement authorization checks on server-side for every request
• Use principle of least privilege for all access decisions
• Validate authorization at resource level, not just at endpoint level
• Implement proper CORS policies to prevent unauthorized cross-origin requests
• Check for insecure direct object references (IDOR vulnerabilities)

Cryptography and Data Protection

• Use industry-standard cryptographic libraries (do not roll your own crypto)
• Use strong encryption algorithms: AES-256 for symmetric, RSA-2048+ or ECC for asymmetric
• Use TLS 1.2 or higher for data in transit
• Encrypt sensitive data at rest (PII, credentials, financial data)
• Never hard-code secrets, API keys, or passwords in source code
• Use environment variables or secret management systems for sensitive configuration

Error Handling and Logging

• Implement centralized error handling
• Never expose sensitive information in error messages (stack traces, database errors, file paths)
• Log security-relevant events (authentication failures, authorization failures, input validation errors)
• Never log sensitive data (passwords, tokens, credit card numbers, PII)
• Implement structured logging for easier analysis

Third-Party Dependencies

• Minimize use of third-party libraries (smaller attack surface)
• Only use well-maintained, reputable libraries with active communities
• Review licenses for compliance
• Keep dependencies up to date with security patches
• Scan dependencies for known vulnerabilities
• Pin dependency versions to prevent unexpected updates

Source Code Management (SLC-02)

Source code managed with organization-approved version control:

• All code stored in version control system (Git, GitHub, GitLab, Bitbucket)
• Use feature branches for development; protect main/production branches
• Require pull requests for all code changes to protected branches
• Never commit secrets, credentials, or API keys to version control
• Use .gitignore to exclude sensitive files and build artifacts
• Maintain clean commit history with meaningful commit messages
• Use signed commits to verify author identity (optional but recommended)

Code Review Requirements

All code changes reviewed before merging to protected branches:

• Peer Review: At least one other developer reviews code changes
• Security Review: Security Champion reviews high-risk changes (authentication, authorization, cryptography, data handling)
• Review Criteria: Code correctness, security best practices, performance, maintainability, test coverage
• Review Checklist: Input validation, output encoding, authentication/authorization checks, error handling, logging, secrets management
• Approval Required: Pull requests require approval from reviewer(s) before merge
• No Self-Merge: Developers cannot approve and merge their own code (segregation of duties)

7. Security Testing and Validation

Automated Security Testing in CI/CD

Security testing integrated into CI/CD pipeline for continuous validation:

Static Application Security Testing (SAST)

• Automated analysis of source code to identify security vulnerabilities
• Tools: SonarQube, Semgrep, Checkmarx, Snyk Code, GitHub Advanced Security
• Scans run on every pull request or commit
• Critical and High severity findings block merge/deployment
• Medium findings tracked and remediated within SLA
• Low findings reviewed during regular security reviews

Software Composition Analysis (SCA)

• Automated scanning of third-party dependencies for known vulnerabilities
• Tools: Snyk, Dependabot, WhiteSource, Black Duck, OWASP Dependency-Check
• Scans run on every build and periodically on deployed applications
• Critical CVEs in dependencies block deployment
• Automated pull requests for dependency updates
• Track and remediate vulnerable dependencies within SLA

Secrets Scanning

• Automated detection of hardcoded secrets in source code
• Tools: GitGuardian, TruffleHog, GitHub Secret Scanning, GitLab Secret Detection
• Scan git history for accidentally committed secrets
• Block commits containing secrets (pre-commit hooks)
• Alert security team when secrets detected
• Rotate exposed secrets immediately

Container and Infrastructure Scanning

• Scan container images for vulnerabilities before deployment
• Tools: Trivy, Clair, Anchore, Snyk Container, AWS ECR scanning
• Scan infrastructure-as-code (Terraform, CloudFormation) for misconfigurations
• Tools: Checkov, tfsec, Terrascan, Bridgecrew
• Block deployment of vulnerable or misconfigured infrastructure

Dynamic Application Security Testing (DAST)

Runtime testing of applications to identify vulnerabilities:

• Automated security testing of running applications in staging/test environments
• Tools: OWASP ZAP, Burp Suite, Acunetix, Qualys WAS
• Tests for OWASP Top 10 vulnerabilities (injection, broken auth, XSS, etc.)
• Run DAST scans before production deployment
• Critical findings must be remediated before production release

Security Unit and Integration Tests

Security-focused tests integrated into test suite:

• Unit tests for authentication and authorization logic
• Tests for input validation and sanitization
• Tests for proper error handling without information disclosure
• Tests for encryption and data protection
• Integration tests for security workflows (login, password reset, MFA)
• Security tests run as part of CI/CD pipeline

Penetration Testing

Periodic penetration testing by internal or external security experts:

• Annual penetration tests for production applications
• Penetration tests after major feature releases or architecture changes
• Internal pentest by security team or external pentest by third-party firm
• Penetration test report documents findings with severity and remediation recommendations
• Critical and High findings remediated within 30 days
• Medium findings remediated within 90 days
• Retest to validate remediation

8. Vulnerability Management in SDLC

Vulnerability Severity and SLA

Vulnerabilities classified by severity with remediation SLAs:

Severity	Description	Remediation SLA	Deployment Block
Critical	Immediate exploitation possible, severe business impact	7 days	Yes
High	Exploitation likely, significant business impact	30 days	Yes
Medium	Exploitation possible, moderate business impact	90 days	No
Low	Low likelihood or minimal impact	180 days or next major release	No

Vulnerability Tracking and Remediation

• All security findings tracked in issue tracking system (Jira, GitHub Issues, etc.)
• Each vulnerability assigned to owner responsible for remediation
• Vulnerabilities tagged with severity, affected component, and remediation deadline
• Security dashboard tracks open vulnerabilities by severity and age
• Overdue vulnerabilities escalated to engineering management
• Vulnerability metrics reported in security reviews and to executive leadership

Risk Acceptance for Vulnerabilities

In limited circumstances, vulnerabilities may be accepted rather than remediated:

• Vulnerability only exploitable under unrealistic conditions
• Compensating controls adequately mitigate risk
• Remediation cost significantly outweighs risk
• Approval Required: Critical/High require CTO approval, Medium require Security Champion approval
• Risk acceptance documented with business justification, compensating controls, review date
• Accepted risks reviewed quarterly and re-assessed when circumstances change

9. Deployment and Release Phase

Pre-Deployment Security Gate

Security checks completed before production deployment:

• All automated security scans passed (SAST, SCA, DAST, container scanning)
• No Critical or High severity unresolved vulnerabilities
• Code review completed and approved
• Security tests passed in CI/CD pipeline
• Change request approved per Change Management Policy
• Deployment runbook includes rollback plan

Secure Deployment Practices

• Use infrastructure-as-code for consistent, auditable deployments (Terraform, CloudFormation, Ansible)
• Apply principle of least privilege to deployment credentials and service accounts
• Use separate environments (dev, staging, production) with appropriate security controls
• Production data never used in non-production environments
• Secrets injected at runtime via secret management system (AWS Secrets Manager, HashiCorp Vault, Azure Key Vault)
• Deploy to production only from protected branches via automated pipeline
• Maintain audit logs of all deployments with who/what/when

Blue-Green and Canary Deployments

Use progressive deployment strategies to minimize risk:

• Blue-Green: Deploy to parallel environment, switch traffic after validation
• Canary: Gradually roll out to small percentage of users, monitor for issues
• Ability to quickly rollback if security issues detected
• Monitor security metrics during rollout (authentication failures, authorization errors, exception rates)

10. Production Monitoring and Incident Response

Security Monitoring

Continuous monitoring of production applications for security events:

• Monitor authentication failures and unusual access patterns
• Monitor authorization failures and privilege escalation attempts
• Monitor input validation errors and potential injection attacks
• Monitor application errors and exceptions that may indicate attacks
• Monitor rate limiting and DoS protection triggers
• Aggregate logs in centralized logging system (ELK, Splunk, Datadog, CloudWatch)
• Set up alerts for suspicious activity

Incident Response Integration

Security incidents detected in production trigger incident response:

• Security incidents logged and tracked per Incident Management Policy
• Security team investigates root cause
• Emergency patches deployed if vulnerability actively exploited
• Post-incident review identifies lessons learned and process improvements
• Vulnerabilities found in production added to security backlog with high priority

11. Third-Party Code and Open Source

Third-Party Library Evaluation

Before adopting new third-party libraries or frameworks:

• Assess library maturity and community activity (GitHub stars, contributors, recent commits)
• Review security advisories and CVE history
• Check license compatibility with organization policies
• Evaluate if library is actively maintained and receives security updates
• Consider alternatives with better security posture
• Document decision and security review

Dependency Updates and Patching

• Regularly update dependencies to latest secure versions
• Subscribe to security advisories for critical dependencies
• Automated dependency update pull requests (Dependabot, Renovate)
• Prioritize security patches over feature updates
• Test dependency updates in staging before production
• Emergency patching process for critical vulnerabilities in dependencies

Software Bill of Materials (SBOM)

Maintain inventory of all software components and dependencies:

• Generate SBOM for each application (CycloneDX, SPDX format)
• Document direct and transitive dependencies
• Track versions and licenses
• Use SBOM for vulnerability tracking and license compliance
• Update SBOM with each release

12. Security Training for Developers

Security Onboarding

All new developers complete security training during onboarding:

• Overview of SSDLC policy and secure development principles
• Secure coding best practices for organization's tech stack
• Common vulnerabilities (OWASP Top 10) and how to prevent them
• Using security tools in CI/CD pipeline
• Code review requirements and security checklist
• Incident reporting and escalation procedures

Ongoing Security Training

• Annual security training for all developers covering latest threats and best practices
• Quarterly security lunch-and-learns or brown bags
• Hands-on security workshops (capture-the-flag, vulnerability labs)
• Share security advisories and lessons learned from incidents
• Training on new security tools and processes

Security Champions Program

Identify and empower security champions within engineering teams:

• Each team has designated security champion
• Security champions receive advanced security training
• Champions act as liaison between security and engineering teams
• Champions promote security best practices within their teams
• Champions participate in security reviews and threat modeling

13. Service Lifecycle Workflow (SLC-01)

Major Release Requirements

Major software releases subject to formal lifecycle workflow:

Concept Accept Phase

• Product requirements documented including security requirements
• Threat model completed for major new features
• Security considerations reviewed with Security Champion
• High-level architecture design reviewed for security implications
• Concept approved by Product and Engineering leadership

Project Plan Commit Phase

• Detailed technical design documented with security controls
• Security work items included in project plan and sprint backlog
• Security testing approach defined (unit tests, integration tests, security scans)
• Deployment plan includes security validation steps
• Project plan approved by Engineering Manager and Security Champion

Implementation Phase

• Development follows secure coding standards
• Code reviews completed for all changes
• Security tests written and executed
• Automated security scans run in CI/CD
• Security findings tracked and remediated

Release Approval Phase

• All security gates passed (no Critical/High vulnerabilities)
• Security testing completed (SAST, DAST, pentest if applicable)
• Security review completed for high-risk changes
• Change request approved per Change Management Policy
• Release approved by Engineering Manager

14. DevSecOps and Automation

Security Automation in CI/CD

Security checks automated in CI/CD pipeline for speed and consistency:

• Pre-commit hooks for secrets scanning and code linting
• Automated SAST and SCA scans on pull requests
• Automated security tests in test suite
• Automated container and infrastructure scanning before deployment
• Automated deployment to staging with DAST scans
• Automated promotion to production after security gate passes
• Security findings surfaced in pull requests and dashboards

Infrastructure as Code (IaC) Security

• All infrastructure provisioned via code (Terraform, CloudFormation, Pulumi)
• IaC stored in version control with code review requirements
• IaC scanned for security misconfigurations (Checkov, tfsec)
• Security baselines and templates for common infrastructure patterns
• Automated compliance checks for cloud configurations (AWS Config, Azure Policy)

Security Dashboards and Metrics

Security metrics tracked and visualized for transparency:

• Open vulnerabilities by severity and age
• Vulnerability remediation time (mean time to remediate)
• Security scan pass/fail rates
• Code coverage for security tests
• Dependency update lag time
• Security training completion rates
• Security incidents related to code vulnerabilities

15. Documentation Requirements

Security Documentation

Security-related design and decisions documented:

• Threat Models: Document threats, attack vectors, and security controls for major features
• Security Architecture Diagrams: Document authentication flows, authorization model, data flows, network architecture
• API Security Documentation: Document authentication requirements, rate limits, input validation
• Security Test Plans: Document security test cases and expected results
• Security Review Notes: Document security reviews, findings, and decisions
• Vulnerability Remediation Plans: Document how vulnerabilities will be addressed

Code Documentation

• Security-sensitive code includes comments explaining security considerations
• Authentication and authorization logic well-documented
• Cryptographic implementations include rationale for algorithm choices
• Input validation and sanitization logic documented

16. Continuous Improvement

Security Retrospectives

Regular review of security practices and incidents:

• Quarterly security retrospectives with engineering teams
• Review security incidents and lessons learned
• Identify process improvements and tooling gaps
• Celebrate security wins and improvements
• Update SSDLC policy based on lessons learned

Security Metrics Review

• Monthly review of security metrics and trends
• Identify teams or areas needing additional support
• Set targets for improvement (reduce vulnerability remediation time, increase test coverage)
• Report security metrics to engineering leadership quarterly

17. Exceptions

Exceptions to this policy require Chief Technology Officer approval with documented business justification, risk assessment, compensating controls, and time-limited review period. Security exceptions tracked and reviewed quarterly.

18. Enforcement

Failure to comply with this policy is grounds for disciplinary action up to and including termination. Bypassing security gates, committing secrets to code, or ignoring security findings is a serious violation. Repeated violations result in removal of repository access and escalation to management.

19. Related Documents

• Change Management Policy
• Vulnerability Management Policy
• Incident Management Policy
• Information Security Management Standard
• Third-Party Service Agreement
• Vendor Information Security Policy

20. Revision History

Date	Version	Author	Description
[Date]	1.0	Chief Technology Officer	Initial release