Kinetis K82 FirmwareOperating system · Nxp

CVE-2021-44479

MEDIUM · 5.5 CVSS v3.1 Published 2021-12-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
NXP Kinetis K82 devices have a buffer over-read via a crafted wlength value in a GET Status-Other request during use of USB In-System Programming (ISP) mode. This discloses protected flash memory.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

NXP Kinetis K82 microcontrollers contain a buffer over-read vulnerability in USB In-System Programming (ISP) mode. When processing a crafted GET Status-Other request with a manipulated wlength value, the USB ISP handler reads beyond buffer boundaries, allowing attackers to extract contents of protected flash memory that should be inaccessible during normal operation.

MitigationApply NXP firmware patches when available. If patching is not immediately feasible, disable USB ISP mode in production deployments and implement physical access controls to prevent unauthorized USB-based exploitation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Kinetis K82 FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device is a NXP Kinetis K82
    Query the USB device descriptor or check the MCU part number via the device programming interface or schematics. The K82 has USB capability and is part of the Kinetis K series.
    Affected if The device is any NXP Kinetis K82 variant (e.g., MK82FN256VLL15).
  2. Verify USB ISP mode is enabled
    Check the USB ISP enable fuse or configuration bit in flash memory. On K82, this is typically controlled via the FSEC or FOPT bytes in the flash configuration field. Read these bytes via the MCU programming interface or attempt to enumerate USB ISP descriptors on the USB interface.
    Affected if USB ISP mode is enabled (the ISP enable bit is not set to disabled/0).
  3. Check if USB ISP interface is accessible
    Connect to the USB port and attempt to communicate with the ISP interface. On K82 devices with USB ISP enabled, the device will enumerate as a USB device with ISP-related descriptors. Use a USB analyzer or attempt to send GET_STATUS request.
    Affected if The device exposes a USB ISP interface and responds to ISP-specific USB requests.
  4. Assess physical access exposure
    Determine if the USB connector for programming is accessible in the deployment environment. Check if USB ISP can be triggered via the USB D+/D- lines without authentication.
    Affected if Physical or USB access to the device is possible in the target deployment.

A user is affected if they have a Kinetis K82 device with USB ISP mode enabled and the USB interface is accessible, allowing an attacker to send crafted GET Status-Other requests to extract protected flash contents.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply NXP firmware patches when available. If patching is not immediately feasible, disable USB ISP mode in production deployments and implement physical access controls to prevent unauthorized USB-based exploitation.

Fix this in Kinetis K82 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-44479 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-44479 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data