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CVE Record

CVE-2021-47177: iommu/vt-d: Fix sysfs leak in alloc_iommu()

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix sysfs leak in alloc_iommu() iommu_device_sysfs_add() is called before, so is has to be cleaned on subsequent errors.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47177 is a Linux kernel issue in Intel VT-d IOMMU handling. During failed initialization, a sysfs entry could be left behind instead of being cleaned up. The public record does not provide a CVSS score, impact rating, or evidence of exploitation.

Executive priority

Treat this as a kernel maintenance item unless internal exposure analysis shows broad affected deployments. The absence of severity scoring and exploitation evidence lowers urgency, but kernel fixes should still flow through normal patch cycles.

Technical view

The fix addresses alloc_iommu() error handling in Linux iommu/vt-d code. iommu_device_sysfs_add() occurs before later failure paths, so those paths must remove the sysfs registration. The source identifies Linux kernel versions including 4.11, 4.14.235, 4.19.193, 5.4.124, 5.10.42, 5.12.9, and 5.13 as affected.

Likely exposure

Exposure is most relevant to Linux systems running affected kernel versions with the Intel VT-d/IOMMU path present. The source bundle does not confirm affected distributions, configurations, or cloud provider images.

Exploitation context

No active exploitation is reported in the provided sources, and the CVE is not listed as KEV. The record describes a cleanup bug, not a public exploit path or attacker workflow.

Researcher notes

Evidence is limited to the CVE record and Linux stable commit references. There is no CVSS vector, CWE, exploit status, or detailed impact statement in the provided bundle. Avoid expanding impact beyond the sysfs cleanup failure described.

Mitigation direction

  • Update to a vendor-supported Linux kernel containing the referenced stable fixes.
  • Check distribution advisories for backported fixes matching your deployed kernel builds.
  • Prioritize virtualization hosts or systems relying on Intel VT-d/IOMMU features.
  • Keep kernel update and reboot tracking tied to asset inventory.

Validation and detection

  • Inventory Linux kernel versions across servers, endpoints, and appliances.
  • Confirm whether deployed kernels include the referenced upstream stable commits.
  • Check distribution package changelogs for CVE-2021-47177 backports.
  • Identify systems using Intel VT-d/IOMMU or virtualization-related kernel features.
Prepared
Confidence
medium
Sources
8

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

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CVE-2021-47177 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
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
7Source 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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux39ab9555c24110671f8dc671311a26e5c985b592, 39ab9555c24110671f8dc671311a26e5c985b592, 39ab9555c24110671f8dc671311a26e5c985b592, 39ab9555c24110671f8dc671311a26e5c985b592, 39ab9555c24110671f8dc671311a26e5c985b592, 39ab9555c24110671f8dc671311a26e5c985b592unaffected
LinuxLinux4.11, 0, 4.14.235, 4.19.193, 5.4.124, 5.10.42, 5.12.9, 5.13affected
Weakness

CWE details

No CWE listed

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