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CVE Record

CVE-2021-47320: nfs: fix acl memory leak of posix_acl_create()

In the Linux kernel, the following vulnerability has been resolved: nfs: fix acl memory leak of posix_acl_create() When looking into another nfs xfstests report, I found acl and default_acl in nfs3_proc_create() and nfs3_proc_mknod() error paths are possibly leaked. Fix them in advance.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47320 is a Linux kernel NFS issue where ACL data can be leaked in specific NFSv3 create or mknod error paths. The public bundle does not provide CVSS, confirmed impact beyond memory leak, or evidence of active exploitation.

Executive priority

Handle through normal kernel patch management, with extra attention to NFS-dependent servers and workstations. The evidence supports a real kernel memory leak fix, but not emergency treatment without confirmed exploit activity or severity scoring.

Technical view

The resolved kernel change frees acl and default_acl objects on error paths in nfs3_proc_create() and nfs3_proc_mknod() after posix_acl_create(). Affected entries include Linux kernel versions from 3.14 through 5.14 as listed in the CVE source bundle.

Likely exposure

Likely relevant to Linux systems running affected kernels and using NFSv3 paths involving POSIX ACL handling. Exposure depends on kernel build, distribution backports, NFS usage, and whether the vulnerable code paths are reachable.

Exploitation context

CISA KEV status is false in the supplied bundle. The sources do not claim public exploitation, exploit availability, attacker prerequisites, or practical denial-of-service impact. Treat exploitability as unconfirmed from the provided evidence.

Researcher notes

The bundle identifies a memory leak in NFSv3 ACL error handling, not memory corruption or privilege escalation. Research should focus on reachability of nfs3_proc_create() and nfs3_proc_mknod() error paths and distribution backport status, without assuming exploitability.

Mitigation direction

  • Update affected Linux kernels through vendor-supported packages or fixed stable releases.
  • Review distribution advisories to map vendor kernel versions to fixed upstream commits.
  • Prioritize systems with NFSv3 usage and POSIX ACL-enabled file creation workflows.
  • Apply normal reboot or live-patching procedures required for kernel fixes.

Validation and detection

  • Inventory Linux kernel versions and compare them with vendor fixed versions.
  • Identify hosts mounting or serving NFSv3 where ACLs are enabled.
  • Confirm the relevant NFS fix is included in the running kernel package.
  • Check vulnerability scanner results against distribution-specific backport information.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-47320 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
10Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9f, 013cdf1088d7235da9477a2375654921d9b9ba9funaffected
LinuxLinux3.14, 0, 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.134, 5.10.52, 5.12.19, 5.13.4, 5.14affected
Weakness

CWE details

No CWE listed

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