Vulnerability in LInux kernel (CVE-2021-4037)
Summary
Vulnerability in LInux kernel (CVE-2021-4037). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A vulnerability was found in the fs/inode.c:inode_init_owner() function logic of the LInux kernel that allows local users to create files for the XFS file-system with an unintended group ownership and with group execution and SGID permission bits set, in a scenario where a directory is SGID and belongs to a certain group and is writable by a user who is not a member of this group. This can lead to excessive permissions granted in case when they should not. This vulnerability is similar to the previous CVE-2018-13405 and adds the missed fix for the XFS.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-4037 has been found in LInux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 4.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "LInux kernel CVE-2021-4037" on the vendor's site.
CVE-2021-4037 (LInux kernel) — CWE-284 / CVSS v3 4.4
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-284) exists in LInux kernel.
Check the vendor advisory for the affected versions of LInux kernel.
Severity: Medium (CVSS 4.4/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで LInux kernel を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2021-4037 linux-aws Fixed in: 4.4.0-1113.119
References
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web bugzilla.redhat.com
- web git.kernel.org
- web git.kernel.org
- web bugzilla.redhat.com
- web lists.debian.org
- web debian.org
- web nvd.nist.gov
- web github.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com