Is CVE-2021-28235 in the CISA KEV catalog?

No. CVE-2021-28235 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-28235?

CVE-2021-28235 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-28235?

CVE-2021-28235 has an EPSS score of 1.60% (73th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-28235?

Upgrade etcd on debian 13 to 3.4.30-1 or later. Fixes are available for 10 affected products.

CVE & CISA-KEV Catalog

CVE-2021-28235

CRITICALEPSS 73th pctl

9.8

CVSS v3

NVD

Description

Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to escalate privileges via the debug function.

CWE-287Improper Authentication

How to fix

Remediation Available

etcdDebian

Fixed in:3.4.30-1CVE-2021-28235

etcdRed Hat / RHEL

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcdRocky

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcd-debuginfoRed Hat / RHEL

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcd-debuginfoRocky

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcd-debugsourceRed Hat / RHEL

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcd-debugsourceRocky

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3445

Fixed in:0:3.3.23-14.el8ostRHSA-2023:3447

Fixed in:0:3.4.26-1.el9ostRHSA-2023:3441

etcdUbuntu

Fixed in:3.2.17+dfsg-1ubuntu0.1+esm2USN-6189-1

Fixed in:3.2.26+dfsg-6ubuntu0.2+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.04.1+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.10.2USN-6189-1

Fixed in:3.4.23-4ubuntu0.1USN-6189-1

etcd-clientUbuntu

Fixed in:3.2.17+dfsg-1ubuntu0.1+esm2USN-6189-1

Fixed in:3.2.26+dfsg-6ubuntu0.2+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.04.1+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.10.2USN-6189-1

Fixed in:3.4.23-4ubuntu0.1USN-6189-1

etcd-serverUbuntu

Fixed in:3.2.17+dfsg-1ubuntu0.1+esm2USN-6189-1

Fixed in:3.2.26+dfsg-6ubuntu0.2+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.04.1+esm1USN-6189-1

Fixed in:3.3.25+dfsg-7ubuntu0.22.10.2USN-6189-1

Fixed in:3.4.23-4ubuntu0.1USN-6189-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

1.60%probability of exploitation in 30 days

73rdpercentile

Elevated risk: more likely to be exploited than 73% of all known CVEs.

References

Product3

Other references2

Related Vulnerabilities

Other CWE-287 (Improper Authentication) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-35082	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-35078	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2017-7921	Critical	9.8	100%	KEV	-
CVE-2024-7593	Critical	9.8	100%	KEV	-
CVE-2023-46805	High	8.2	100%	KEV + Ransom	-
CVE-2022-40684	Critical	9.8	100%	KEV + Ransom	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-05.