CVE intelligence and bounded remediation

CVE-2018-16886 — Etcd Etcd security vulnerability

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 role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.

Severity
High
CVSS
8.1 (3.1)
Published
2019-01-14
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-287

Affected products

  • etcd / etcd
  • redhat / enterprise_linux_desktop / 7.0
  • redhat / enterprise_linux_server / 7.0
  • redhat / enterprise_linux_workstation / 7.0
  • fedoraproject / fedora / 30

Showing 5 representative product identities from 6 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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