Impact

Antrea's network policy priority assignment system has a uint16 arithmetic overflow bug that causes incorrect OpenFlow priority calculations when handling a large numbers of policies with various priority values. This results in potentially incorrect traffic enforcement.

If a user creates a large number of Antrea NetworkPolicies (ANP or ACNP) with varying priorities, some rules with lower logical priorities (higher numerical priority values) may take precedence over rules with higher logical priorities (lower numerical priority values). Traffic that should be denied by the configured Antrea NetworkPolicies may end up being allowed, potentially letting an attacker access a sensitive service. Traffic that should be allowed by the configured Antrea NetworkPolicies may end up being denied, breaking applications and potentially opening the door for denial-of-service attacks.

The Antrea NetworkPolicy system comes with support for priority Tiers. Rules defined within a Tier cannot take precedence over rules defined in higher priority Tiers. Some users / roles may only be authorized to define within specific Tiers. This security vulnerability enables such users to intentionally "escape" their Tier and override rules in higher priority Tiers.

Antrea deployments that only use upstream Kubernetes NetworkPolicies - and do not use Antrea NetworkPolicies - are not affected.

Patches https://github.com/antrea-io/antrea/pull/7496 Antrea v2.5.0 Antrea v2.4.3 Antrea v2.3.2

Workarounds

Antrea deployments that only use upstream Kubernetes NetworkPolicies - and do not use Antrea NetworkPolicies - are not affected.

For users leveraging Antrea NetworkPolicies, there is no way to fix or remediate the vulnerability without upgrading.

Resources

https://gist.github.com/antoninbas/c429cc3e5bb8479ba7ff38fd6fde59d9 https://github.com/antrea-io/antrea/pull/7496 https://github.com/antrea-io/antrea/blob/main/docs/antrea-network-policy.md

Impact This is a missing encryption vulnerability (CWE-311) affecting inter-Node Pod traffic. In Antrea clusters configured for dual-stack networking with IPsec encryption enabled (trafficEncryptionMode: ipsec), Antrea fails to apply encryption for IPv6 Pod traffic.

While the IPv4 traffic is correctly encrypted via ESP (Encapsulating Security Payload), traffic using IPv6 is transmitted in plaintext. This occurs because the packets are encapsulated (using Geneve or VXLAN) but bypass the IPsec encryption layer.

Impacted Users: users with dual-stack clusters and IPsec encryption enabled.

Single-stack IPv4 or IPv6 clusters are not affected.

Patches Yes, the issue has been patched: https://github.com/antrea-io/antrea/pull/7759 Users should upgrade to one of the following versions: Antrea v2.6.0 or later Antrea v2.5.2 Antrea v2.4.5

Antrea recommends running the antctl check installation --run ipsec tool after upgrading to verify that both address families are correctly producing ESP traffic.

Workarounds There is no configuration workaround to enable IPsec IPv6 in affected versions. If an immediate upgrade is not possible, user may consider using WireGuard instead for inter-Node Pod traffic encryption. The WireGuard support in Antrea does not suffer from the same issue.

Resources Pull Request with Fix: antrea-io/antrea#7759 Validation Tool PR: antrea-io/antrea#7757 Antrea Documentation: Traffic Encryption Guide