CVE-2021-20201

MEDIUMNVD 5.35.3—

5.3

A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.

CVSS v3: 5.3
EG Score: 5.3(medium)
EPSS: 75.5%
KEV: Not listed

Published

May 28, 2021

Last Modified

November 21, 2024

References (6)

secalert@redhathttps://blog.qualys.com/product-tech/2011/10/31/tls-renegotiation-and-denial-of-service-attacks
secalert@redhathttps://bugzilla.redhat.com/show_bug.cgi?id=1921846
secalert@redhathttps://security.gentoo.org/glsa/202208-10
af854a3a-2127-422b-91ae-364da2661108https://blog.qualys.com/product-tech/2011/10/31/tls-renegotiation-and-denial-of-service-attacks
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.redhat.com/show_bug.cgi?id=1921846
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202208-10

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
redhat	spice-0:0.14.3-4.el8	2021-05-18	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.

Weakness Classification(1)

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

CWE-400Uncontrolled Resource Consumption (Denial of Service)

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Red HatRHSA-2021:1924LOW2020-12-01
RHSA-2021:1924 — Low

Data Freshness Timeline

(refreshed 10× 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.

2026-06-04 13:10 UTCepss_batch
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
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 15:56 UTCEG score recompute
2026-05-26 15:56 UTCVendor advisory
2026-05-26 15:56 UTCGHSA enrichment
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-20201?

CVE-2021-20201 is a medium vulnerability published on May 28, 2021. A flaw was found in spice in versions before 0.14.92. A DoS tool might make it easier for remote attackers to cause a denial of service (CPU consumption) by performing many renegotiations within a single connection.

When was CVE-2021-20201 disclosed?

CVE-2021-20201 was first published in the National Vulnerability Database on May 28, 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-2021-20201 actively exploited?

CVE-2021-20201 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 75.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-20201?

CVE-2021-20201 has a CVSS v3 base score of 5.3 (NVD).

How do I remediate CVE-2021-20201?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20201, 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

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CVE-2021-20201

Published

Last Modified

References (6)

Patch Availability(1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-20201?

Same vendor

Same CWE

CVE-2021-20201

📅 Published

🔄 Last Modified

🔗 References (6)

Patch Availability(1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-20201?

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References (6)

Frequently asked(5)

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