Source and Dependency Management
Version Pinning Dependency versions should be pinned to specific versions rather than ranges. Pinning prevents unexpected updates that could introduce vulnerabilities or malicious code. Lock files including package-lock.json, Gemfile.lock, and go.sum should be committed to version control. Lock files ensure reproducible builds. Automated dependency updates should use pull requests with review and testing. Automation enables timely updates while maintaining control. Vetted Package Mirrors Internal package mirrors provide vetted, scanned packages. Mirrors enable security scanning before packages reach developers. Mirror policies should allow-list approved packages. Allow-listing prevents use of unapproved packages. Mirror scanning should include vulnerability scanning and malware detection. Scanning prevents malicious packages. Signature Verification Package signatures should be verified before installation. Signature verification proves package authenticity. Unsigned packages should be rejected or flagged for review. Unsigned packages cannot be trusted. Signature verification should use trusted key infrastructure. Compromised keys enable malicious packages. Typosquatting Prevention Typosquatting detection identifies packages with names similar to popular packages. Detection prevents accidental installation of malicious packages. Package name validation should check for suspicious patterns. Validation prevents typosquatting. Developer education about typosquatting reduces risk. Awareness is first defense. Transitive Dependency Review Software Bill of Materials (SBOM) enumerates all dependencies including transitive dependencies. SBOM provides visibility into complete dependency tree. SBOM should be generated automatically during build. Automation ensures accuracy. SBOM formats including SPDX and CycloneDX enable tool interoperability. Standard formats enable ecosystem integration. Transitive dependency review identifies unexpected or suspicious dependencies. Review prevents supply chain attacks through deep dependencies.Build Security and Provenance
Hermetic Builds Hermetic builds use only declared dependencies without network access during build. Hermetic builds prevent undeclared dependencies. Build environments should be isolated and ephemeral. Isolation prevents cross-contamination. Build reproducibility enables verification that artifacts match source code. Reproducibility enables independent verification. Build Isolation Build runners should be isolated from each other and from production systems. Isolation prevents lateral movement from compromised builds. Ephemeral build environments are created fresh for each build and destroyed afterward. Ephemeral environments prevent persistence. Minimal network access during build reduces attack surface. Network access should be limited to declared dependencies. SLSA Provenance SLSA (Supply-chain Levels for Software Artifacts) defines levels of supply chain security maturity. SLSA provides framework for supply chain security. SLSA provenance attestations document build process including source repository, commit hash, build system, and build steps. Provenance enables verification. Provenance should be cryptographically signed by build system. Signatures prove provenance authenticity. SLSA Level 3 requires isolated builds with provenance. Level 3 provides strong supply chain security. Artifact Signing Build artifacts including container images, binaries, and packages should be cryptographically signed. Signing proves artifact authenticity. Signing keys should be protected in HSMs or cloud key management. Key protection prevents unauthorized signing. Signatures should be verified before deployment. Verification prevents deployment of unsigned or tampered artifacts. Tamper-Evident Registries Artifact registries should be tamper-evident with immutable storage. Immutability prevents artifact modification. Registry access should be authenticated and authorized. Access control prevents unauthorized uploads. Registry audit logs track all operations. Audit logs enable investigation of suspicious activity.Deployment Verification
Admission Control Admission controllers verify signatures and provenance before allowing deployment. Admission control enforces supply chain policies. Policies should allow only artifacts from trusted builders and signers. Trust should be explicitly defined. Unsigned or unverified artifacts should be rejected. Rejection prevents deployment of untrusted code. Policy as Code Supply chain policies should be defined as code and version-controlled. Code-based policies enable automation and auditability. Policies should specify allowed registries, required signatures, and provenance requirements. Comprehensive policies prevent bypasses. Policy violations should be logged and alerted. Logging enables detection of policy bypass attempts. Runtime Verification Runtime verification ensures that running code matches deployed artifacts. Verification detects runtime tampering. Allow-lists specify permitted executables and libraries. Allow-lists prevent execution of unauthorized code. Drift detection identifies differences between desired state and actual state. Drift indicates potential compromise. Continuous Verification Verification should be continuous rather than one-time at deployment. Continuous verification detects post-deployment tampering. Periodic re-verification ensures ongoing compliance. Re-verification catches drift.Incident Response and Updates
Vulnerability Advisory Ingestion Vulnerability advisories from sources including NVD, GitHub Security Advisories, and vendor notifications should be ingested automatically. Automation enables rapid response. Advisory correlation matches advisories to deployed dependencies. Correlation identifies affected systems. Severity assessment prioritizes response based on exploitability and impact. Prioritization focuses effort. Bulk Update Tooling Bulk update tools enable rapid patching across many repositories and services. Bulk updates reduce exposure window. Automated pull requests for dependency updates accelerate patching. Automation reduces manual effort. Update testing should be automated to validate updates. Testing prevents update-induced breakage. Feature Flags and Rollback Feature flags enable rapid disablement of vulnerable functionality without full rollback. Flags provide surgical response. Safe rollback procedures enable rapid reversion to known-good versions. Rollback reduces incident impact. Rollback testing ensures that rollback procedures work. Untested rollback fails during incidents. Production Inventory Production inventory tracks all deployed artifacts with versions and dependencies. Inventory enables rapid impact assessment. Inventory should be automatically maintained and continuously updated. Manual inventory becomes stale. Inventory queries enable rapid identification of affected systems during incidents. Query capability accelerates response.Supply Chain Security Tools
SBOM Generation SBOM tools including Syft, CycloneDX, and SPDX generators create software bills of materials. SBOM tools should integrate with build pipelines. SBOM should be generated for all artifacts. Comprehensive SBOM enables complete visibility. Dependency Scanning Dependency scanners including Dependabot, Renovate, and Snyk identify vulnerable dependencies. Scanning should be continuous. Scanners should check both direct and transitive dependencies. Transitive dependencies are often overlooked. Signing and Verification Signing tools including Sigstore Cosign and Notary enable artifact signing. Signing should be integrated into build pipelines. Verification tools validate signatures at deployment. Verification should be automated. Policy Enforcement Policy enforcement tools including OPA, Kyverno, and Gatekeeper enforce supply chain policies. Enforcement should be automated and comprehensive.Conclusion
Software supply chain security requires comprehensive controls across dependencies, build systems, and deployment pipelines with cryptographic verification at every stage. Security engineers implement defense-in-depth assuming that any component could be compromised. Success requires hermetic builds, SLSA provenance, artifact signing, admission control, and rapid response capabilities. Organizations that invest in supply chain security fundamentals prevent supply chain attacks that bypass traditional security controls.References
- SLSA (Supply-chain Levels for Software Artifacts)
- in-toto Framework
- OpenSSF Scorecards
- NIST SSDF (Secure Software Development Framework) SP 800-218
- Sigstore Project
- SPDX and CycloneDX SBOM Standards