CVE-2021-34845
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 PDF Reader 11.0.0.49893. 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 Annotation objects. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-14034.
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 confidenceThis is a use-after-free or null pointer dereference vulnerability in Foxit PDF Reader's Annotation object handling. The lack of validating the existence of an object prior to performing operations on it allows arbitrary code execution when a user opens a malicious PDF file or visits a malicious webpage embedding a 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<= 11.0.0.49893<= 10.1.4.37651= 11.0.0.49893CVSS 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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Check Foxit PDF Reader versionOpen Foxit PDF Reader, go to Help > About Foxit Reader, or right-click the application in the taskbar and select About. Note the version number displayed.Affected if The installed version is 11.0.0.49893 or lower.
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Check Foxit PDF Editor versionOpen Foxit PDF Editor, go to Help > About Foxit PDF Editor, or right-click the application in the taskbar and select About. Note the version number displayed.Affected if The installed version is 10.1.4.37651 or lower, or exactly 11.0.0.49893.
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Identify if vulnerable software is presentCheck Programs and Features (Windows) or examine the installed applications list for any Foxit PDF Reader or Foxit PDF Editor installation.Affected if Either Foxit PDF Reader version 11.0.0.49893 or lower, or Foxit PDF Editor version 10.1.4.37651 or lower or exactly 11.0.0.49893 is installed.
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Confirm the attack surfaceThe vulnerability is triggered when a user opens a malicious PDF file. No additional configuration needs to be enabled; the built-in PDF rendering and annotation handling is the affected component.Affected if Users open PDF files from untrusted sources using the installed Foxit software.
A user is affected if Foxit PDF Reader version 11.0.0.49893 or lower, or Foxit PDF Editor version 10.1.4.37651 or lower or exactly 11.0.0.49893 is installed and users open PDF files.
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 PDF Reader to the latest version. Avoid opening untrusted PDF files from unknown sources.
- Consultation3.0 h
- Implementation6.0 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-2021-34845 — 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-2021-34845 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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