CVE-2021-34966
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 · uneditedFoxit PDF Editor FileAttachment Annotation Use-After-Free Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit PDF Editor. 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-14367.
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 vulnerability in Foxit PDF Editor's handling of Annotation objects allows remote code execution. The flaw stems from the lack of validation of object existence prior to performing operations on the object, leading to a UAF condition that can be leveraged to execute code 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<= 10.1.5.37672= 11.0.0.49893= 11.0.1.49938<= 11.0.1.49938CVSS 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:3.0/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 Foxit PDF application installedOpen Foxit PDF Editor or Reader, click Help > About Foxit PDF Editor (or Reader) to view the exact version number displayed in the dialog windowAffected if The application name shows Foxit PDF Editor or Foxit PDF Reader
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Compare version against affected rangesNote the full version number (for example: 10.1.5.37672, 11.0.0.49893, or 11.0.1.49938) and compare against the affected versions: any version <= 10.1.5.37672, exactly 11.0.0.49893, or exactly 11.0.1.49938Affected if The installed version matches one of these: <= 10.1.5.37672, = 11.0.0.49893, or = 11.0.1.49938 for Editor; <= 11.0.1.49938 for Reader
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Verify annotation handling is in useThe vulnerability affects the Annotation feature which is a standard PDF feature loaded by default when opening any PDF file containing annotations - no configuration check needed as this is default behaviorAffected if The application opens or processes PDF files, which triggers the vulnerable annotation handling code path
If the installed Foxit PDF Editor or Reader version falls within the affected ranges (Editor: <= 10.1.5.37672, 11.0.0.49893, or 11.0.1.49938; Reader: <= 11.0.1.49938), the environment is vulnerable to the use-after-free flaw in Annotation object handling.
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 dataApply the vendor patch or update Foxit PDF Editor to the latest version. Until then, exercise caution when opening PDF files from untrusted sources.
- Consultation2.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34966 — 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-2021-34966 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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