9.8

CVE-2021-28235: etcd Improper Authentication

CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2021-28235USN-6189-1DEBIAN-CVE-2021-28235
Published 04-04-2023Last modified 09-07-2026
Open JSON

Vulnerability summary

CVE-2021-28235 is a critical (CVSS 9.8) Improper Authentication vulnerability in etcd. EPSS estimates a 1.62% chance of exploitation in the next 30 days, higher than 75.6% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
1.62%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 2
OPENSUSE-SU-2025:0003-1RHSA-2023:3441RHSA-2023:3445RHSA-2023:3447SUSE-SU-2024:3656-1

Timeline

  1. 04-04-2023
    PublishedVulnerability first disclosed.
  2. 09-07-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

1.62%

Chance of exploitation in the next 30 days

Percentile

76%

Versus all other CVEs

30-day change

0.00 pp

From 1.62% on 18-09-2026

18-09-202618-10-2026
EPSS score
1.62%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Opensuse4 products
  • etcd-for-k8s1.25&distro=openSUSE Tumbleweed< 3.5.9-1.1
  • etcd-for-k8s1.26&distro=openSUSE Tumbleweed< 3.5.9-1.1
  • etcd-for-k8s1.27&distro=openSUSE Tumbleweed< 3.5.9-1.1
  • etcd&distro=openSUSE Tumbleweed< 3.5.8-1.1
Debian1 product
  • etcdAll versions (No fix recorded) | < 3.4.30-1
Etcd1 product
Go.etcd.io/etcd1 product
  • v33.4.10
Ubuntu1 product
  • etcdAll versions (No fix recorded) | < 3.2.17+dfsg-1ubuntu0.1+esm2 | < 3.2.26+dfsg-6ubuntu0.2+esm1 | < 3.3.25+dfsg-7ubuntu0.22.04.1+esm1

5 vendors · 8 products

References

14 links
Show all 14 references