CVE-2021-31473
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 browseForDoc function. The issue results from the lack of proper validation of user-supplied data, which can result in a write 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-13523.
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 confidenceBuffer overflow vulnerability in Foxit Reader's browseForDoc function due to lack of proper validation of user-supplied data, allowing write past end of allocated buffer and arbitrary code execution in current process context. Requires user to open malicious PDF file or visit malicious page.
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<= 9.7.5.29616>= 10.0.0.0, <= 10.1.3.37598<= 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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Identify installed Foxit productOpen Foxit Reader or PhantomPDF, then go to Help > About, or check Windows Registry at HKLM\SOFTWARE\FoxitSoftware\Reader\CurrentVersion (adjust key for PhantomPDF)Affected if Product is Foxitsoftware Reader or Foxitsoftware Phantompdf with version <= 10.1.3.37598, or PhantomPDF version <= 9.7.5.29616, or PhantomPDF version >= 10.0.0.0 and <= 10.1.3.37598
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Confirm version is within affected rangeCompare the installed version number found in step 1 against the vulnerable ranges: Reader <= 10.1.3.37598; PhantomPDF <= 9.7.5.29616 OR >= 10.0.0.0 and <= 10.1.3.37598Affected if Installed version falls into any of these ranges
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Verify browseForDoc function is accessibleThe browseForDoc function is invoked when using File > Open or the open file dialog to load a PDF document. This feature is enabled by default in standard usage.Affected if The application can be used to open PDF files, which is the default behavior and required condition for exploitation
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Check for evidence of malicious PDF filesReview recently opened PDF files in the application's recent files list (File > Recent Files) or examine any suspicious PDF files that may have been opened from untrusted sourcesAffected if The user has opened a PDF from an untrusted or unknown source, which is the attack vector required to trigger the buffer overflow
A user is affected if Foxit Reader or PhantomPDF is installed with a version matching the affected ranges and the application has been used to open PDF files, particularly from untrusted sources.
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 latest patched version; avoid opening PDF files from untrusted sources.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-31473 — 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-2021-31473 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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