CVE-2021-34833
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-14023.
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 confidenceA use-after-free or null pointer dereference vulnerability in Foxit PDF Reader 11.0.0.49893 allows remote attackers to execute arbitrary code via a maliciously crafted PDF file. The flaw exists in the Annotation object handling where the application fails to validate object existence before performing operations on it, leading to code execution in the context of the current process.
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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Identify installed Foxit productOpen Windows Settings > Apps & Features or use 'Get-ItemProperty' in PowerShell for HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\* to locate Foxit PDF Reader or Foxit PDF EditorAffected if Either Foxit PDF Reader or Foxit PDF Editor is present on the system
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Locate Foxit version numberIn Foxit, go to Help > About Foxit PDF Reader (or About Foxit PDF Editor). Alternatively, check the executable properties of foxitreader.exe or foxitpdfeditor.exe in Program FilesAffected if Version cannot be determined or differs from the installed product
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Compare Reader version to affected rangeIf Foxit PDF Reader is installed, compare the installed version against 11.0.0.49893 - any version equal to or lower than this is affectedAffected if Foxit PDF Reader version is <= 11.0.0.49893
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Compare Editor version to affected rangesIf Foxit PDF Editor is installed, compare the installed version against 10.1.4.37651 and 11.0.0.49893 - any version equal to or lower than 10.1.4.37651, or exactly 11.0.0.49893, is affectedAffected if Foxit PDF Editor version is <= 10.1.4.37651 or equals 11.0.0.49893
The system is vulnerable if Foxit PDF Reader version <= 11.0.0.49893 or Foxit PDF Editor version <= 10.1.4.37651 or exactly 11.0.0.49893 is installed.
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 dataAvoid opening untrusted PDF files and update Foxit PDF Reader to the latest patched version. Enable security warnings and restrict PDF execution from untrusted sources.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34833 — 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-2021-34833 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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