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Network Access

It is good security practice to prevent your containers from communicating with the internet by default.

However, some evals may require internet access (e.g. to install packages or research topics). The built-in Helm chart allows you to specify a list of domains that your containers can access.

Cilium

The built-in Helm chart uses Cilium Network Policies to restrict network access.

Cilium has tooling to observe network requests, such as Hubble. Though note from the limitations section that domain names will not be shown when using the built-in Helm chart due to how DNS resolution is handled.

See the limitations section for how Cilium may make certain Cyber misuse evals harder or impossible to solve.

DNS Exfiltration

The built-in Helm chart prevents DNS exfiltration attacks. This is where an attacker uses DNS lookups to an attacker-controlled domain or set of subdomains in order to exfiltrate data from a system. For example, a malicious agent could make DNS requests (which go via the kube-dns service if the Core DNS sidecar can't resolve them) to hostnames like somedata.attacker.com and somedata2.attacker.com to exfiltrate data.

DNS lookups are restricted to only:

  • Services within the Kubernetes namespace
  • The domains specified in the allowDomains list in the values.yaml file.

See the limitations section for how this may affect your evals.

I don't want to restrict DNS lookups

The list of DNS names that can be queried is controlled by the same allow-list as general traffic egress to a domain. In order to allow all DNS lookups without restriction (including reverse DNS), you will need to allow all traffic to the internet.

Please consider the security implications: your containers will have unrestricted internet access (including the ability to use DNS to exfiltrate data).

To allow all DNS queries and all internet access, set allowDomains: ["*"] or allowEntities: "all" in the values.yaml file.