Docker Sandboxes (sbx) enforces an HTTP/S-only egress allowlist but does not apply it to DNS resolution: the per-network embedded DNS server forwards any queried name to the host resolver whenever the network is internet-connected, without consulting the policy. A workload inside a sandbox, which the threat model treats as untrusted, can therefore encode data into DNS labels for an attacker-controlled domain and exfiltrate it through a DNS covert channel, bypassing the configured allowlist.
Weakness
The product establishes a communication channel to (or from) an endpoint for privileged or protected operations, but it does not properly ensure that it is communicating with the correct endpoint.
Extended Description
Attackers might be able to spoof the intended endpoint from a different system or process, thus gaining the same level of access as the intended endpoint. While this issue frequently involves authentication between network-based clients and servers, other types of communication channels and endpoints can have this weakness.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/161.html
- https://cwe.mitre.org/data/definitions/481.html
- https://cwe.mitre.org/data/definitions/501.html
- https://cwe.mitre.org/data/definitions/697.html