CVE-2021-31466
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 · uneditedThis vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit Reader 10.1.3.37598. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of U3D objects in PDF files. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-13583.
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 · high confidenceOut-of-bounds read vulnerability in Foxit Reader's handling of U3D (Universal 3D) objects embedded in PDF files. The lack of proper validation of user-supplied data allows reading past the end of an allocated data structure, which can be leveraged for arbitrary code execution in the context of the current process. User interaction required (opening malicious PDF).
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<= 9.7.4.29600>= 10.0.0.0, <= 10.1.3.37598CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Confirm Foxit Reader installationCheck for Foxit Reader in installed programs (Control Panel > Programs and Features) or run: reg query 'HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\FoxitReader' /v DisplayNameAffected if Foxit Reader is installed and version falls within <= 9.7.4.29600 or >= 10.0.0.0 and <= 10.1.3.37598
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Identify installed Foxit Reader versionRun: reg query 'HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\FoxitReader' /v DisplayVersion (or check Help > About in the application)Affected if Version number is 9.7.4.29600 or lower, OR between 10.0.0.0 and 10.1.3.37598 inclusive
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Determine if 3D/U3D content rendering is enabledIn Foxit Reader, go to File > Preferences > 3D and check if 'Enable 3D content' or similar U3D rendering option is checked/enabledAffected if U3D/3D content rendering is enabled in Reader preferences (the vulnerability only triggers when this feature processes a malicious PDF)
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Inspect PDF files for embedded U3D objects (optional)Use a PDF analysis tool or open the PDF in a hex editor and search for the string 'U3D' or look for 3D object streamsAffected if U3D objects are present in PDF files opened by the user (required for exploitation)
You are affected if Foxit Reader version is 9.7.4.29600 or lower, or between 10.0.0.0 and 10.1.3.37598, AND U3D/3D content rendering is enabled, AND you open a PDF containing a malicious U3D object.
Generated from the published advisory. Verify against your own configuration.
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 dataUpdate Foxit Reader to the latest version; avoid opening untrusted PDF files or disable U3D content rendering in Reader settings until patched.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-31466 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-31466 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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