How severe is CVE-2021-28235?

CVE-2021-28235 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-28235 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28235?

CVE-2021-28235 affects Etcd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28235?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-28235 published?

CVE-2021-28235 was published on 2023-04-04 and last updated on 2026-07-05.

CVE-2021-28235

CVE-2021-28235 is a critical-severity vulnerability in Etcd with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Etcd
Published: 2023-04-04
Last modified: 2026-07-05

Description

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

Frequently asked questions

What is CVE-2021-28235?: Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to escalate privileges via the debug function.
How severe is CVE-2021-28235?: CVE-2021-28235 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-28235 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28235?: CVE-2021-28235 affects Etcd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28235?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-28235 published?: CVE-2021-28235 was published on 2023-04-04 and last updated on 2026-07-05.

References

Affected products (1)

cpe:2.3:a:etcd:etcd:3.4.10:*:*:*:*:*:*:*

More vulnerabilities in Etcd

CVE-2026-33413 — High (CVSS 8.8): etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42, 3.5.28, and…
CVE-2018-16886 — High (CVSS 8.1): etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when…
CVE-2022-34038 — High (CVSS 7.5): Etcd v3.5.4 allows remote attackers to cause a denial of service via function PageWriter.write in pagewriter.go. NOTE:…
CVE-2020-15112 — Medium (CVSS 6.5): In etcd before versions 3.3.23 and 3.4.10, it is possible to have an entry index greater then the number of entries in…
CVE-2020-15106 — Medium (CVSS 6.5): In etcd before versions 3.3.23 and 3.4.10, a large slice causes panic in decodeRecord method. The size of a record is…
CVE-2020-15113 — Medium (CVSS 5.7): In etcd before versions 3.3.23 and 3.4.10, certain directory paths are created (etcd data directory and the directory…

All CVEs affecting Etcd →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →