CVE intelligence and bounded remediation

CVE-2021-4197 — Linux Linux Kernel security vulnerability

High CVSS 7.8

An unprivileged write to the file handler flaw in the Linux kernel's control groups and namespaces subsystem was found in the way users have access to some less privileged process that are controlled by cgroups and have higher privileged parent process. It is actually both for cgroup2 and cgroup1 versions of control groups. A local user could use this flaw to crash the system or escalate their privileges on the system.

Severity
High
CVSS
7.8 (3.1)
Published
2022-03-23
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-287

Affected products

  • linux / linux_kernel
  • oracle / communications_cloud_native_core_binding_support_function / 22.1.1
  • oracle / communications_cloud_native_core_binding_support_function / 22.1.3
  • oracle / communications_cloud_native_core_binding_support_function / 22.2.0
  • debian / debian_linux / 10.0
  • broadcom / brocade_fabric_operating_system_firmware

Showing 6 representative product identities from 15 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

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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