Assetnote ASM vs cnames: 2026 Comparison
Assetnote ASM is a commercial external attack surface management tool by Assetnote. cnames is a free external attack surface management tool. 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:
Mid-market and enterprise security teams managing sprawling external infrastructure will get the most from Assetnote ASM because its hourly asset discovery actually catches exposures before your business units spin up new services, not weeks after. The platform covers ID.AM and DE.CM across NIST CSF 2.0, meaning you're building a real asset inventory while monitoring it continuously, and the exploit-based verification eliminates the noise that buries actionable findings in traditional scanners. Skip this if your organization lacks the headcount to operationalize a workflow-driven program; Assetnote's strength is enabling lean teams to prioritize, not giving you a dashboard to ignore.
Security teams managing large subdomain inventories who need to quickly identify third-party service dependencies will find cnames valuable for that single, unglamorous job. The tool does one thing well: bulk CNAME resolution at no cost, which means you can run it repeatedly without justifying recurring spend to procurement. This is a CLI utility, not a platform; it won't replace your external attack surface management tool, but it will save time in the reconnaissance phase before you feed results into one.
