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CVE Record

CVE-2021-47485: IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields

In the Linux kernel, the following vulnerability has been resolved: IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields Overflowing either addrlimit or bytes_togo can allow userspace to trigger a buffer overflow of kernel memory. Check for overflows in all the places doing math on user controlled buffers.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-47485 is a Linux kernel flaw in the IB/qib code. A local userspace-controlled buffer calculation can overflow and lead to kernel memory buffer overflow. The sources do not provide CVSS, public exploitation evidence, or business-impact details.

Executive priority

Handle through normal kernel patch governance, with higher priority for multi-user or high-performance Linux systems using IB/qib. No source supports emergency treatment for active exploitation.

Technical view

The issue is integer overflow handling around struct qib_user_sdma_pkt fields addrlimit and bytes_togo. Overflow in math on user-controlled buffers could trigger kernel memory buffer overflow. Linux stable commits add overflow checks across the relevant calculations.

Likely exposure

Exposure is most likely on Linux systems running affected kernel versions where IB/qib functionality is present and reachable by local userspace. Internet-facing remote exposure is not indicated by the provided sources.

Exploitation context

The source describes userspace triggering kernel memory overflow, so treat this as local attack surface. The CVE is not listed as KEV, and the bundle provides no evidence of active exploitation or public exploit availability.

Researcher notes

The record lacks CVSS and CWE mappings. Analysis should focus on the stable commit deltas and reachable qib userspace paths. Avoid assuming privilege escalation or remote reach without additional vendor evidence.

Mitigation direction

  • Apply Linux kernel or distribution updates containing the referenced stable fixes.
  • Prioritize systems using IB/qib functionality or affected kernel branches.
  • Check vendor advisories for supported fixed package versions.
  • If IB/qib is unnecessary, review vendor-supported options to disable exposure.

Validation and detection

  • Inventory Linux kernel versions across servers and appliances.
  • Check whether affected kernels include the referenced stable commits.
  • Identify systems where IB/qib functionality is loaded or required.
  • Confirm distribution security updates are installed and active after reboot.
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-2021-47485 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
9Source 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
LinuxLinuxf931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5d, f931551bafe1f10ded7f5282e2aa162c267a2e5dunaffected
LinuxLinux2.6.35, 0, 4.4.292, 4.9.290, 4.14.255, 4.19.216, 5.4.157, 5.10.77, 5.14.16, 5.15affected
Weakness

CWE details

No CWE listed

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