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CVE Record

CVE-2021-47432: lib/generic-radix-tree.c: Don't overflow in peek()

In the Linux kernel, the following vulnerability has been resolved: lib/generic-radix-tree.c: Don't overflow in peek() When we started spreading new inode numbers throughout most of the 64 bit inode space, that triggered some corner case bugs, in particular some integer overflows related to the radix tree code. Oops.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-47432 is a Linux kernel availability issue. A local low-privileged user could trigger an integer-overflow corner case in generic radix tree handling related to large inode numbers, causing a kernel oops. The sources do not indicate data theft, data modification, or active exploitation.

Executive priority

Treat as a routine but real availability patch. It is not a remote takeover issue in the provided evidence, but kernel denial of service can still disrupt shared or production Linux hosts.

Technical view

The flaw is in lib/generic-radix-tree.c peek() overflow handling. The CVSS vector is local, low attack complexity, low privileges required, no user interaction, unchanged scope, and high availability impact only. Kernel stable commits are listed as the resolution references.

Likely exposure

Exposure is limited to Linux systems running affected kernel versions or downstream builds that have not incorporated the referenced stable fixes. Shared systems with untrusted local users deserve closer review because exploitation requires local low-privileged access.

Exploitation context

The source bundle does not list CISA KEV status or any cited evidence of active exploitation. The realistic concern is local denial of service through a kernel oops, not remote compromise.

Researcher notes

Evidence is sparse beyond the kernel resolution text and stable commit references. The affected-version data in the bundle is broad and should be reconciled against distribution backports before declaring a specific packaged kernel vulnerable or fixed.

Mitigation direction

  • Update affected Linux kernels using vendor or distribution guidance.
  • Confirm the deployed kernel includes the referenced stable fix commits.
  • Prioritize shared hosts where low-privileged local access is available.
  • Reboot systems after kernel updates so the fixed kernel is active.
  • Monitor vendor advisories for backported package names and fixed releases.

Validation and detection

  • Inventory running kernel versions across Linux assets.
  • Compare versions against CVE and distribution advisory affected ranges.
  • Check package changelogs for the referenced generic-radix-tree fix.
  • Verify systems rebooted into the updated kernel after patching.
  • Review local-user exposure on multi-user or shared workload systems.
Prepared
Confidence
medium
Sources
6

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-2021-47432 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

1CVSS vectors
3Timeline events
2ADP providers
5Source links

SSVC decision data

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

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2021-47432Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

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
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxba20ba2e3743bac786dff777954c11930256075e, ba20ba2e3743bac786dff777954c11930256075e, ba20ba2e3743bac786dff777954c11930256075e, ba20ba2e3743bac786dff777954c11930256075eunaffected
LinuxLinux5.1, 0, 6.1.64, 6.5.13, 6.6.3, 6.7affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.