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CVE Record

CVE-2021-47404: HID: betop: fix slab-out-of-bounds Write in betop_probe

In the Linux kernel, the following vulnerability has been resolved: HID: betop: fix slab-out-of-bounds Write in betop_probe Syzbot reported slab-out-of-bounds Write bug in hid-betopff driver. The problem is the driver assumes the device must have an input report but some malicious devices violate this assumption. So this patch checks hid_device's input is non empty before it's been used.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-47404 is a Linux kernel flaw in the Betop HID game-controller driver. A malicious HID device that omits an expected input report can trigger a slab out-of-bounds write during device probing. The sources do not provide CVSS, business impact scoring, or evidence of active exploitation.

Executive priority

Treat this as a targeted local/device-exposure kernel issue, not an internet-wide emergency based on the supplied evidence. Patch through normal kernel maintenance, with higher urgency for labs, kiosks, developer workstations, and other systems exposed to untrusted peripherals.

Technical view

The hid-betopff driver assumed a probed HID device had at least one input report. Syzbot found that a malicious device could violate this assumption, leading to a slab-out-of-bounds write in betop_probe. The referenced kernel stable fixes add a non-empty input check before use.

Likely exposure

Exposure is most plausible on Linux systems where affected kernels load the Betop HID force-feedback driver and accept untrusted or malicious HID devices. The source bundle does not indicate a remote network attack path.

Exploitation context

The CVE record says malicious devices can trigger the bad assumption. CISA KEV status is false in the bundle, and no cited source states active exploitation. Practical exploitation likely depends on device attachment or HID emulation access.

Researcher notes

Evidence is limited to the CVE description and Linux stable references. The root cause is a missing validation check in betop_probe before using HID input data. No CWE, CVSS, exploit maturity, or detailed affected branch mapping is provided in the bundle.

Mitigation direction

  • Update affected Linux kernels using distribution packages containing the referenced stable fixes.
  • Prioritize systems that accept untrusted USB, Bluetooth, or other HID peripherals.
  • Check vendor guidance for driver disablement if Betop HID support is unnecessary.
  • Avoid accepting untrusted HID devices on sensitive Linux workstations and servers.

Validation and detection

  • Inventory Linux kernel versions across managed systems.
  • Confirm distribution advisories or changelogs reference CVE-2021-47404 or the stable commits.
  • Identify endpoints where untrusted HID devices can be attached.
  • After patching, regression-test required HID and game-controller workflows.
Prepared
Confidence
medium
Sources
10

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-2021-47404 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
LinuxLinux52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4, 52cd7785f3cdd2724f4efb5b21dbc75d6f9ccef4unaffected
LinuxLinux4.0, 0, 4.4.286, 4.9.285, 4.14.249, 4.19.209, 5.4.151, 5.10.71, 5.14.10, 5.15affected
Weakness

CWE details

No CWE listed

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