Understanding Alert Uniqueness: Same Host & Port, Different IPs

In modern infrastructures, a single hostname frequently resolves to multiple IP addresses. These IPs are not interchangeable from a security perspective. Treating them as duplicates and excluding them from testing would create significant blind spots. Each unique combination of scheme, host, port, and IP must be scanned to accurately assess risk.

Key Technical Reasons

1. Load Balancers and Geo-DNS
   Large environments often use round-robin DNS or geo-distributed load balancers to improve performance and resilience. Different IPs can point to different backend pools or regions, each with its own patch level, configuration, or WAF policy.
   Example: One pool might have a patched TLS library while another is still running a vulnerable version.
2. CDN and Anycast Edge Nodes
   Content Delivery Networks often deploy gradual updates across their global edge servers. Edge nodes can temporarily differ in TLS ciphers, certificates, headers, or cache rules. Vulnerabilities can appear only at specific locations or during phased rollouts.
3. Disaster Recovery and Staging Servers
   DR sites or staging environments may share the same hostname for cut-over or testing. These servers are often less hardened, running older builds or exposing diagnostic endpoints that attackers can exploit.
4. Blue/Green and Canary Deployments
   During incremental deployments some nodes may serve a new build while others remain on the old version. Issues introduced in the new build—or unpatched flaws in the old—will only be visible if every IP is tested.
5. Configuration Drift
   Even within a single environment, nodes can drift over time. Examples include expired or mismatched TLS certificate chains, missing security headers, inconsistent redirects, or weaker cipher suites on just one IP.
6. Network Path and Control Variance
   Access control lists, DDoS protection, rate limits, and firewall rules may differ between IPs. Attackers will probe all available addresses to find the weakest path.

Security Impact of Ignoring IP Variants

Attackers routinely enumerate all DNS records and directly target each IP until they find a misconfigured or less protected node. If only a subset of IPs is scanned, vulnerabilities on the untested nodes will remain undetected, creating exploitable gaps and giving a false sense of security.

Recommendation

For complete coverage and accurate risk assessment, ShadowMap must scan every IP associated with a given hostname, even when the hostname and port appear identical. This ensures that configuration differences, regional rollouts, or overlooked disaster-recovery nodes cannot be used as entry points by attackers.