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CVE Record

CVE-2021-47474: comedi: vmk80xx: fix bulk-buffer overflow

In the Linux kernel, the following vulnerability has been resolved: comedi: vmk80xx: fix bulk-buffer overflow The driver is using endpoint-sized buffers but must not assume that the tx and rx buffers are of equal size or a malicious device could overflow the slab-allocated receive buffer when doing bulk transfers.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47474 is a Linux kernel driver flaw in comedi vmk80xx. A malicious device could cause a receive-buffer overflow during USB bulk transfers. The source bundle does not provide a CVSS score, impact rating, or evidence of real-world exploitation, so urgency depends on whether affected systems use this driver and accept untrusted devices.

Executive priority

Treat as targeted infrastructure hygiene rather than an internet-scale emergency. Patch during normal kernel maintenance unless systems use this driver with untrusted device exposure, where remediation should be prioritized sooner.

Technical view

The vmk80xx comedi driver used endpoint-sized buffers while assuming transmit and receive buffers were equal size. The kernel fix addresses a slab-allocated receive-buffer overflow risk during bulk transfers when interacting with a malicious device. Multiple stable kernel commit references are provided, but the bundle does not detail exploit primitives or downstream distribution package status.

Likely exposure

Exposure appears limited to affected Linux kernels where the comedi vmk80xx driver is present and reachable through relevant hardware interaction. Internet-facing exposure is not indicated. The provided affected-version data is incomplete for distribution packages, so vulnerability managers should map kernel package versions to vendor fixes.

Exploitation context

The bundle states a malicious device could trigger the overflow during bulk transfers. It does not cite public exploitation, weaponized code, or KEV listing. Because KEV is false and no cited source reports exploitation, active exploitation should not be assumed.

Researcher notes

Evidence supports a kernel memory-safety bug fixed in stable commits. The bundle lacks CVSS, CWE, exploit status, and distribution-specific fixed versions. Avoid broad claims beyond malicious-device-triggered bulk-transfer overflow in the comedi vmk80xx driver.

Mitigation direction

  • Update to a vendor-supported Linux kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for exact fixed package versions.
  • Restrict use of untrusted devices on systems that may load this driver.
  • Prioritize systems with direct device access or specialized data-acquisition hardware.

Validation and detection

  • Inventory Linux kernel versions across affected fleets.
  • Confirm whether the comedi vmk80xx driver is present or loaded.
  • Map installed kernel packages to distribution fixed versions or referenced commits.
  • Review asset classes with physical or peripheral device exposure.
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-2021-47474 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
LinuxLinux985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fb, 985cafccbf9b7f862aa1c5ee566801e18b5161fbunaffected
LinuxLinux2.6.31, 0, 4.4.292, 4.9.290, 4.14.255, 4.19.217, 5.4.159, 5.10.79, 5.14.18, 5.15.2, 5.16affected
Weakness

CWE details

No CWE listed

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