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CVE Record

CVE-2021-47286: bus: mhi: core: Validate channel ID when processing command completions

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Validate channel ID when processing command completions MHI reads the channel ID from the event ring element sent by the device which can be any value between 0 and 255. In order to prevent any out of bound accesses, add a check against the maximum number of channels supported by the controller and those channels not configured yet so as to skip processing of that event ring element.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47286 is a Linux kernel MHI bus issue where a connected device can report an invalid channel ID. Without validation, the kernel could process data outside the configured channel range. Business urgency depends on whether affected Linux systems use MHI-capable hardware and drivers.

Executive priority

Treat as targeted kernel maintenance rather than an internet-wide emergency. Prioritize patch validation for Linux endpoints, embedded systems, and servers using MHI-connected devices, especially where device input is less trusted.

Technical view

The MHI core read a channel ID from a device-supplied event ring element, allowing values from 0 to 255. The fix adds checks against the controller's maximum channel count and skips channels not configured, preventing out-of-bounds access during command completion processing.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with MHI controller/device support active. The provided source lists Linux kernel versions and stable commits, but does not identify specific distributions, appliances, or hardware models.

Exploitation context

The source bundle does not report active exploitation, public exploit use, CVSS, CWE, or KEV listing. The issue requires interaction with MHI device event data, so practical risk depends on device trust boundaries and hardware deployment.

Researcher notes

Evidence supports an out-of-bounds access prevention fix in Linux MHI command completion handling. The bundle does not provide impact class, crash evidence, privilege boundary details, or exploitability analysis, so severity remains uncertain.

Mitigation direction

  • Update to a Linux kernel containing the referenced stable fixes.
  • Check distribution advisories for backported kernel fixes.
  • Prioritize systems with active MHI hardware or drivers.
  • Track vendor guidance for affected appliances or embedded builds.

Validation and detection

  • Inventory Linux kernel versions across exposed fleets.
  • Check whether MHI kernel support is enabled and loaded.
  • Confirm installed kernels include the referenced stable commits or vendor backports.
  • Review kernel and device logs for MHI-related instability.
Prepared
Confidence
medium
Sources
5

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

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CVE-2021-47286 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
4Source 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
LinuxLinux1d3173a3bae7039b765a0956e3e4bf846dbaacb8, 1d3173a3bae7039b765a0956e3e4bf846dbaacb8, 1d3173a3bae7039b765a0956e3e4bf846dbaacb8unaffected
LinuxLinux5.7, 0, 5.10.54, 5.13.6, 5.14affected
Weakness

CWE details

No CWE listed

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