net/http: limit growth of header canonicalization cache
CVE: CVE-2021-44716
Component: golang
CWE: CWE-400
Severity: Important
CVSS v3: 7.5/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Release date: 2021-12-09T00:00:00+00:00

There's an uncontrolled resource consumption flaw in golang's net/http library in the canonicalHeader() function. An attacker who submits specially crafted requests to applications linked with net/http's http2 functionality could cause excessive resource consumption that could lead to a denial of service or otherwise impact to system performance and resources.

Statement: For OpenShift Container Platform, OpenShift Virtualization, Red Hat Quay and OpenShift distributed tracing the most an attacker can possibly achieve by exploiting this vulnerability is to crash a container, temporarily impacting availability of one or more services. Therefore impact is rated Moderate.

In its default configuration, grafana as shipped in Red Hat Enterprise Linux 8 is not affected by this vulnerability. However, enabling http2 in /etc/grafana/grafana.ini explicitly would render grafana affected, therefore grafana has been marked affected.

Remediation:
For OpenShift Container Platform 4.10 see the following documentation,
which will be updated shortly for this release, for important instructions
on how to upgrade your cluster and fully apply this asynchronous errata
update:

https://docs.openshift.com/container-platform/4.10/release_notes/ocp-4-10-release-notes.html

Details on how to access this content are available at
https://docs.openshift.com/container-platform/4.10/updating/updating-cluster-cli.html
Before applying this update, you must apply all previously released errata
relevant to your system.

To apply this update, refer to:

https://access.redhat.com/articles/11258
Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258
For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://docs.openshift.com/container-platform/latest/sandboxed_containers/upgrade-sandboxed-containers.html
See the Red Hat OpenShift Container Platform 4.6 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.6/html/serverless/index
See the Red Hat OpenShift Container Platform 4.7 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.7/html/serverless/index
See the Red Hat OpenShift Container Platform 4.8 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.8/html/serverless/index
See the Red Hat OpenShift Container Platform 4.9 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.9/html/serverless/index
See the Red Hat OpenShift Container Platform 4.10 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.10/html/serverless/index
See the Red Hat OpenShift Container Platform 4.6 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.6/html/serverless/index
See the Red Hat OpenShift Container Platform 4.7 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.7/html/serverless/index
See the Red Hat OpenShift Container Platform 4.8 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.8/html/serverless/index
See the Red Hat OpenShift Container Platform 4.9 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.9/html/serverless/index
See the Red Hat OpenShift Container Platform 4.10 documentation at:
https://access.redhat.com/documentation/en-us/openshift_container_platform/4.10/html/serverless/index
For details on how to install and use MTC, refer to:

https://docs.openshift.com/container-platform/latest/migration_toolkit_for_containers/installing-mtc.html
OSP 16.2.z Release - OSP Director Operator Containers
For OpenShift Container Platform 4.10 see the following documentation,
which will be updated shortly for this release, for important instructions
on how to upgrade your cluster and fully apply this asynchronous errata
update:

https://docs.openshift.com/container-platform/4.10/release_notes/ocp-4-10-release-notes.html

Details on how to access this content are available at
https://docs.openshift.com/container-platform/4.10/updating/updating-cluster-cli.html
For OpenShift Container Platform 4.10 see the following documentation,
which will be updated shortly for this release, for moderate instructions
on how to upgrade your cluster and fully apply this asynchronous errata
update:

https://docs.openshift.com/container-platform/4.10/release_notes/ocp-4-10-release-notes.html

Details on how to access this content are available at
https://docs.openshift.com/container-platform/4.10/updating/updating-cluster-cli.html
For OpenShift Container Platform 4.9 see the following documentation, which
will be updated shortly for this release, for important instructions on how
to upgrade your cluster and fully apply this asynchronous errata update:

https://docs.openshift.com/container-platform/4.9/release_notes/ocp-4-9-release-notes.html

Details on how to access this content are available at
https://docs.openshift.com/container-platform/4.9/updating/updating-cluster-cli.html
The Service Telemetry Framework container image provided by this update can be downloaded from the Red Hat Container Registry at registry.access.redhat.com. Installation instructions for your platform are available at Red Hat Container Catalog (see References).
Dockerfiles and scripts should be amended either to refer to this new image specifically, or to the latest image generally.
The Service Telemetry Framework container image provided by this update can be downloaded from the Red Hat Container Registry at registry.access.redhat.com. Installation instructions for your platform are available at Red Hat Container Catalog (see References).
Dockerfiles and scripts should be amended either to refer to this new image specifically, or to the latest image generally.
This flaw can be mitigated by disabling HTTP/2. Setting the GODEBUG=http2server=0 environment variable before calling Serve will disable HTTP/2 unless it was manually configured through the golang.org/x/net/http2 package.