CVE-2021-33195

HIGHNVD 7.37.3—

7.3

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.

CVSS v3: 7.3
EG Score: 7.3(medium)
EPSS: 9.3%
KEV: Not listed

Published

August 2, 2021

Last Modified

November 21, 2024

References (8)

cve@mitrehttps://groups.google.com/g/golang-announce
cve@mitrehttps://groups.google.com/g/golang-announce/c/RgCMkAEQjSI
cve@mitrehttps://security.gentoo.org/glsa/202208-02
cve@mitrehttps://security.netapp.com/advisory/ntap-20210902-0005/
af854a3a-2127-422b-91ae-364da2661108https://groups.google.com/g/golang-announce
af854a3a-2127-422b-91ae-364da2661108https://groups.google.com/g/golang-announce/c/RgCMkAEQjSI
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202208-02
af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20210902-0005/

Vendor Advisories for CVE-2021-33195(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

CVE-2021-33195
Microsoft Security Response Center (MSRC)
CVE-2021-33195

Patch Availability(25)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
redhat	buildah-1:1.27.0-2.el9	2022-11-15	redhat
redhat	kubevirt-0:2.6.10-230.el8	2022-04-19	redhat
redhat	kubevirt-0:4.8.5-278.el8	2022-04-12	redhat
redhat	openshift4-wincw/windows-machine-config-rhel8-operator:5.0.0-5	2022-03-28	redhat
redhat	container-native-virtualization/virt-cdi-importer:v4.9.2-8	2022-01-19	redhat
redhat	mcg-0:5.9.0-28.61dcf87.5.9.el8	2021-12-13	redhat
redhat	odf/odf-multicluster-rhel8-operator:4.9-30.007b3d8.release_4.9	2021-12-13	redhat
redhat	etcd-0:3.3.23-3.1.el8ost.1	2021-12-09	redhat
redhat	go-toolset:rhel8-8050020210817155413.8aa62369	2021-11-09	redhat
redhat	grafana-0:7.5.9-4.el8	2021-11-09	redhat
redhat	container-native-virtualization/virt-cdi-uploadserver:v4.9.0-37	2021-11-02	redhat
redhat	butane-0:0.12.1-2.rhaos4.8.el8	2021-10-19	redhat
redhat	openshift4/ose-etcd:v4.9.0-202109302317.p0.git.5c1feaf.assembly.stream	2021-10-18	redhat
redhat	container-native-virtualization/vm-import-operator-rhel8:v4.8.2-4	2021-09-21	redhat
redhat	openshift-serverless-clients-0:0.23.2-1.el8	2021-09-16	redhat
redhat	openshift-serverless-1/svls-must-gather-rhel8:1.17.0-5	2021-09-16	redhat
redhat	go-toolset-1.15-golang-0:1.15.14-2.el7_9	2021-09-07	redhat
redhat	golang-github-prometheus-promu-0:0.5.0-4.git642a960.el8	2021-08-31	redhat
redhat	rhmtc/openshift-velero-plugin-rhel8:v1.5.1-4	2021-08-31	redhat
redhat	distributed-tracing/jaeger-rhel8-operator:1.20.5-5	2021-08-19	redhat
redhat	ignition-0:2.6.0-8.rhaos4.6.git947598e.el8	2021-08-12	redhat
redhat	advanced-cluster-security/rhacs-rhel8-operator:3.64.0-2	2021-08-12	redhat
redhat	redhat-release-coreos-0:47.84-1.el8	2021-08-11	redhat
redhat	openshift4/ovirt-csi-driver-rhel8-operator:v4.8.0-202107291502.p0.git.7b6cd3d.assembly.stream	2021-08-10	redhat
redhat	openshift-clients-0:4.8.0-202107292313.p0.git.1077b05.assembly.stream.el7	2021-08-10	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)

Go(1)

Package	Vulnerable range	Fixed in	Dependents
stdlib	—	1.16.5	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

Additional Vendor Advisories

(24)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 12:49 UTCEG score recompute
2026-05-26 12:49 UTCVendor advisory
2026-05-26 12:49 UTCGHSA enrichment
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-33195?

CVE-2021-33195 is a high vulnerability published on August 2, 2021. 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.

When was CVE-2021-33195 disclosed?

CVE-2021-33195 was first published in the National Vulnerability Database on August 2, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-33195 actively exploited?

CVE-2021-33195 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 9.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

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

CVE-2021-33195 has a CVSS v3 base score of 7.3 (NVD).

How do I remediate CVE-2021-33195?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-33195, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-33195

Explore →

Is Your Infrastructure Affected by CVE-2021-33195?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2021-33195

Published

Last Modified

References (8)

Vendor Advisories for CVE-2021-33195(1)

Patch Availability(25)

Affected Packages

Weakness Classification(1)

Additional Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-33195?

Same vendor

Same CWE

CVE-2021-33195

📅 Published

🔄 Last Modified

🔗 References (8)

📣 Vendor Advisories for CVE-2021-33195(1)

Patch Availability(25)

Affected Packages

Weakness Classification(1)

Additional Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-33195?

🔗 Related CVEs(same vendor + same CWE)

Same vendor

Same CWE

Published

Last Modified

References (8)

Vendor Advisories for CVE-2021-33195(1)

Frequently asked(5)

Related CVEs(same vendor + same CWE)