Containers (i.e. kubernetes pods) that request HostPort forwarding can intercept all traffic destined for that port. This requires that the portmap plugin be explicitly configured to use the nftables backend. (The iptables backend is the default.)
A vulnerability was found in all versions of containernetworking/plugins before version 0.8.6, that allows malicious containers in Kubernetes clusters to perform man-in-the-middle (MitM) attacks. A malicious container can exploit this flaw by sending rogue IPv6 router advertisements to the host or other containers, to redirect traffic to the malicious container.
Clusters using Calico (version 3.14.0 and below), Calico Enterprise (version 2.8.2 and below), may be vulnerable to information disclosure if IPv6 is enabled but unused. A compromised pod with sufficient privilege is able to reconfigure the node’s IPv6 interface due to the node accepting route advertisement by default, allowing the attacker to redirect full or partial network traffic from the node to the compromised pod.