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AutocadApplication · Autodesk

CVE-2021-40166

HIGH · 7.8 CVSS v3.1 Published 2022-10-07
Fix available
A fix is available. Upgrade to 2019.1.4 / 2020.1.5 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
A maliciously crafted PNG file in Autodesk Image Processing component may be used to attempt to free an object that has already been freed while parsing them. This vulnerability may be exploited by attackers to execute arbitrary code.

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

This is a use-after-free (UAF) vulnerability in Autodesk's Image Processing component where a maliciously crafted PNG file can trigger a double-free condition during parsing. When the PNG file is processed, the component attempts to free an object that has already been freed, leading to memory corruption that can be leveraged for arbitrary code execution.

MitigationApply the vendor-supplied patch for affected Autodesk products. Until patched, exercise caution with PNG files from untrusted sources and consider disabling or restricting the Image Processing component where possible.

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
AutocadApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad Advance SteelApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad ArchitectureApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad Civil 3dApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad ElectricalApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad LtApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2020, < 2020.3.2>= 2021, < 2021.1.2>= 2021, < 2021.2.2>= 2022, < 2022.1.2>= 2022, < 2022.2.2
Autocad Map 3dApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2
Autocad MechanicalApplication
Affected:>= 2019, < 2019.1.4>= 2020, < 2020.1.5>= 2021, < 2021.1.2>= 2022, < 2022.1.2

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
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Identify installed Autodesk AutoCAD product
    Open the application and go to Help > About Autodesk AutoCAD, or check Add/Remove Programs (Windows) for the installed product name and version
    Affected if Any Autodesk AutoCAD variant (AutoCAD, AutoCAD Architecture, Civil 3D, Electrical, LT, Mechanical, Map 3D, Advance Steel) is installed
  2. Determine the exact product version
    In the application, type 'VER' or 'ABOUT' at the command line, or check the Windows installed programs list for the full version number including the update/patch level (e.g., 2019.1.4, 2020.1.5)
    Affected if The installed version falls within any of these ranges: 2019.x before 2019.1.4, 2020.x before 2020.1.5, 2021.x before 2021.1.2, 2022.x before 2022.1.2; for AutoCAD LT also: 2020.x before 2020.3.2, 2021.x before 2021.2.2, 2022.x before 2022.2.2
  3. Check for recent security updates
    Run the application's update checker (HELP > CHECK FOR UPDATES) or review Autodesk account/portal for installed hotfixes or service packs
    Affected if No vendor patches or service packs have been applied to address this vulnerability

You are affected if you have any Autodesk AutoCAD variant (including verticals) installed with version 2019 before 1.4, 2020 before 1.5 (or 3.2 for LT), 2021 before 1.2 (or 2.2 for LT), or 2022 before 1.2 (or 2.2 for LT), and the Image Processing component can load PNG files.

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.

dbcve · scoped
Upgrade available Upgrade to 2019.1.4 / 2020.1.5 / 2020.3.2 or later
Fixed in 2019.1.42020.1.52020.3.2
Interim mitigation

Apply the vendor-supplied patch for affected Autodesk products. Until patched, exercise caution with PNG files from untrusted sources and consider disabling or restricting the Image Processing component where possible.

Recommended fix High confidence

Upgrade to version 2019.1.4 (for 2019.x), 2020.1.5 or 2020.3.2 (for 2020.x), 2021.1.2 (for 2021.x), or 2022.1.2 (for 2022.x) depending on your product line

  1. Identify the specific Autodesk product and current installed version from Help > About Autodesk > Product Information
  2. Visit the Autodesk Support website (www.autodesk.com) and navigate to the Downloads & Updates section for your specific product
  3. Search for and download the appropriate hotfix/patch based on your current version: for 2019.x download 2019.1.4, for 2020.x download 2020.1.5 (or 2020.3.2 for LT), for 2021.x download 2021.1.2, for 2022.x download 2022.1.2
  4. Close all Autodesk applications before running the installer
  5. Run the installer and follow the on-screen instructions to apply the patch
  6. Restart the computer after installation completes
  7. Verify the patch was applied by checking Help > About Autodesk > Product Information shows the fixed version number
Caveat Point releases typically include backward-compatible fixes; verify critical custom scripts or workflows after upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Autocad Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2021-40166 in production — separate from our analysis above.

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What this is

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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