CVE-2020-8554

2020-12-0720:21:43

redhat.com

access.redhat.com

5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

LOW

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

6 Medium

CVSS2

Access Vector

NETWORK

Access Complexity

MEDIUM

Authentication

SINGLE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:N/AC:M/Au:S/C:P/I:P/A:P

0.002 Low

EPSS

Percentile

61.6%

JSON

A flaw was found in kubernetes. If a potential attacker can already create or edit services and pods, then they may be able to intercept traffic from other pods (or nodes) in the cluster.

Mitigation

ExternalIP addresses ranges can be configured as described below. OCP 4 is secure by default, though cluster-admins can whitelist externalIP addresses as needed. OCP 3.11 can be secured by changing externalIPNetworkCIDR to "0.0.0.0/32", which blocks all externalIP address values.

<https://docs.openshift.com/container-platform/4.6/networking/configuring_ingress_cluster_traffic/configuring-externalip.html>
<https://docs.openshift.com/container-platform/3.11/admin_guide/tcp_ingress_external_ports.html#service-externalip>

Users can check if they have permission to patch the Status of a LoadBalancer Service with the command: kubectl auth can-i patch service --subresource=status. In OCP, by default only cluster-admins are granted this permission.