A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local range, but the same validation was not performed on EndpointSlice IPs.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private     networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local     range, but the same validation was not performed on EndpointSlice IPs. (CVE-2021-25737)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Redhat Enterprise Linux 7 / 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:2437 advisory.

    Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution     designed for on-premise or private cloud deployments.

    This advisory contains the RPM packages for Red Hat OpenShift Container Platform 4.8.2. See the following     advisory for the container images for this release:

    https://access.redhat.com/errata/RHSA-2021:2438

    Security Fix(es):

    * gogo/protobuf: plugin/unmarshal/unmarshal.go lacks certain index validation (CVE-2021-3121)

    * golang: crypto/elliptic: incorrect operations on the P-224 curve (CVE-2021-3114)

    * openshift: Injected service-ca.crt incorrectly contains additional internal CAs (CVE-2021-3636)

    * python-eventlet: improper handling of highly compressed data and memory allocation with excessive size     allows DoS (CVE-2021-21419)

    * jenkins-2-plugins/matrix-auth: Incorrect permission checks in Matrix Authorization Strategy Plugin     (CVE-2021-21623)

    * jenkins-2-plugins/credentials: Reflected XSS vulnerability in Credentials Plugin (CVE-2021-21648)

    * kubernetes: Validating Admission Webhook does not observe some previous fields (CVE-2021-25735)

    * jenkins: lack of type validation in agent related REST API (CVE-2021-21639)

    * jenkins: view name validation bypass (CVE-2021-21640)

    * kubernetes: Holes in EndpointSlice Validation Enable Host Network Hijack (CVE-2021-25737)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    All OpenShift Container Platform 4.8 users are advised to upgrade to these updated packages and images     when they are available in the appropriate release channel. To check for available updates, use the     OpenShift Console or the CLI oc command. Instructions for upgrading a cluster are available at     https://docs.openshift.com/container-platform/4.8/updating/updating-cluster-between-     minor.html#understanding-upgrade-channels_updating-cluster-between-minor

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the kubernetes package has been released.

ID	Name	Product	Family	Severity
255914	Linux Distros Unpatched Vulnerability : CVE-2021-25737	Nessus	Misc.	medium
152103	RHEL 7 / 8 : OpenShift Container Platform 4.8.2 (RHSA-2021:2437)	Nessus	Red Hat Local Security Checks	high
151962	Photon OS 1.0: Kubernetes PHSA-2021-1.0-0413	Nessus	PhotonOS Local Security Checks	medium

Detections

Analytics

CVE-2021-25737

medium

Tenable Plugins

medium

high

medium