s3viewer vs Siemba EASM: 2026 Comparison
s3viewer is a free external attack surface management tool. Siemba EASM is a commercial external attack surface management tool by Siemba. Compare features, ratings, integrations, and community reviews side by side to find the best external attack surface management fit for your security stack.
CST VerdictBased on our analysis of NIST CSF 2.0 coverage, core features, company size fit, deployment model, here is our conclusion:
Security teams conducting external attack surface reconnaissance on cloud infrastructure should use s3viewer for its speed in discovering publicly exposed storage across multiple cloud providers and protocols from a single interface. The tool is free and requires no credentials to operate, making it immediately deployable for red team assessments or initial exposure audits without procurement friction. Skip this if you need ongoing monitoring or remediation workflows; s3viewer is a point-in-time discovery tool, not a continuous posture management platform.
