CVE-2021-44716

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Last Modified: UTC

ImportantImportant ImpactWhat does this mean?

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Description

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.

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.

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.

Mitigation

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.

Additional information

  • Bugzilla 2030801: golang: net/http: limit growth of header canonicalization cache
  • CWE-400: Uncontrolled Resource Consumption
  • FAQ: Frequently asked questions about CVE-2021-44716

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

7.5

7.5

Attack Vector

Network

Network

Attack Complexity

Low

Low

Privileges Required

None

None

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

High

High

CVSS v3 Vector

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

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

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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