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No exploitation reportedFix available

CVE-2021-33195

No exploitation reported by the sources we read.

  • Published2021-08-02
  • Fixed in1.16.5 · 1.15.13
  • WeaknessCWE-74

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Go before 1.15.13 and 1.16.x before 1.16.5 has functions for DNS lookups that do not validate replies from DNS servers, and thus a return value may contain an unsafe injection (e.g., XSS) that does not conform to the RFC1035 format.

Timeline

dates in UTC
  1. 2021-08-0219:15CVE publishedNVD

Versions per branch

NVD · OSV
Go
BranchAffectedFixed in
1.16≥ 1.16.0, < 1.16.51.16.5
1.16≥ 1.16.0-0, < 1.16.51.16.5
1.15< 1.15.131.15.13
Netapp cloud insights telegraf agent
BranchAffectedFixed in
—all versionsno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • atomic-openshift-service-idlerRed Hat:openshift:4.7::el8all versions · fixed in 0:4.7.0-202107291238.p0.git.39cfc66.assembly.stream.el8
  • buildahRed Hat:enterprise_linux:9::appstreamall versions · fixed in 1:1.27.0-2.el9and 4 other packages
  • buildahAlmaLinux:9all versions · fixed in 1:1.27.0-2.el9and 1 other package
  • butaneRed Hat:openshift:4.8::el8all versions · fixed in 0:0.12.1-2.rhaos4.8.el8and 1 other package
  • containernetworking-pluginsRed Hat:openshift:4.8::el7all versions · fixed in 0:0.8.6-3.rhaos4.6.el7and 1 other package
  • cri-oRed Hat:openshift:4.8::el8all versions · fixed in 0:1.21.2-8.rhaos4.8.git8d4264e.el8and 2 other packages
  • cri-oRed Hat:openshift:4.8::el7all versions · fixed in 0:1.21.2-8.rhaos4.8.git8d4264e.el7and 1 other package
  • cri-oRed Hat:openshift:4.7::el8all versions · fixed in 0:1.20.4-7.rhaos4.7.git6287500.el8and 2 other packages

73 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-33195 Red Hat Product Security771 products fixed · 104 known affected

    golang: net: lookup functions may return invalid host names

    rhmtc/openshift-migration-controller-rhel8 as a component of Migration Toolkit for Containers · rhmtc/openshift-migration-velero-plugin-for-mtc-rhel8 as a component of Migration Toolkit for Containers · knative-eventing as a component of OpenShift Serverless · +101 more

  • RHSA-2022:8008 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: buildah security and bug fix update

  • RHSA-2022:1402 Red Hat Product Security6 products fixed

    Red Hat Security Advisory: OpenShift Virtualization 2.6.10 RPMs security and bug fix update

  • RHSA-2022:1329 Red Hat Product Security6 products fixed

    Red Hat Security Advisory: OpenShift Virtualization 4.8.5 RPMs security update

  • RHSA-2022:0577 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: Windows Container Support for Red Hat OpenShift 5.0.0 [security update]

  • RHSA-2022:0947 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: OpenShift Virtualization 4.10.0 Images security and bug fix update

22 more advisories

Full record on NVD

Fix

  1. Update Go to 1.16.5 · 1.15.13
  2. Vendor fix Red Hat Product Security RHSA-2022:8008 · 21 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. Vendor fix Red Hat Product Security RHSA-2022:0577 · 2 productsFor Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/latest/windows_containers/windows-node-upgrades.html
  4. Vendor fix Red Hat Product Security RHSA-2021:5072 · 7 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  5. Vendor fix Red Hat Product Security RHSA-2021:3820 · 7 productsFor OpenShift Container Platform 4.8 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/4.8/release_notes/ocp-4-8-r…
  6. Vendor fix Red Hat Product Security RHSA-2021:3759 · 4 productsFor 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-r…
  7. Vendor fix Red Hat Product Security RHSA-2021:3598 · 1 productFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://docs.openshift.com/container-platform/4.8/virt/upgrading-virt.html

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2021-08-02
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-xf7m-5vgf-jhv9

Frequently asked questions

What is CVE-2021-33195?

Go before 1.15.13 and 1.16.x before 1.16.5 has functions for DNS lookups that do not validate replies from DNS servers, and thus a return value may contain an unsafe injection (e.g., XSS) that does not conform to the RFC1035 format.

Is CVE-2021-33195 actively exploited?

Active exploitation of CVE-2021-33195 has not been confirmed. Its EPSS score was 3.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-33195?

CVE-2021-33195 has a CVSS v3 base score of 7.3 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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