CVE-2018-20313
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 Reader before 9.5, and PhantomPDF before 8.3.10 and 9.x before 9.5, has a proxyPreviewAction race condition that can cause a stack-based buffer overflow or an out-of-bounds read.
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 race condition in the proxyPreviewAction function of Foxit Reader before 9.5 and PhantomPDF before 8.3.10/9.x before 9.5 allows an attacker to trigger either a stack-based buffer overflow or an out-of-bounds read, potentially leading to code execution or information disclosure.
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< 8.3.10>= 9.0, < 9.5< 9.5CVSS 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
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/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.
-
Confirm Foxit Reader or PhantomPDF is installedOpen Windows Control Panel > Programs and Features, or check C:\Program Files\Foxit Software for the existence of Foxit Reader or PhantomPDF foldersAffected if Either Foxit Reader or PhantomPDF software is present on the system
-
Identify the exact installed version of Foxit ReaderRight-click the Foxit Reader shortcut, select Properties, and check the version in the Details tab. Alternatively, open Foxit Reader and go to Help > About Foxit Reader to display the full version numberAffected if The displayed version number is below 9.5 (for example, 9.4.x, 9.3.x, 9.2.x, 9.1.x, 9.0.x, or any version below 9.0)
-
Identify the exact installed version of PhantomPDFRight-click the PhantomPDF shortcut, select Properties, and check the version in the Details tab. Alternatively, open PhantomPDF and go to Help > About Foxit PhantomPDF to display the full version numberAffected if The displayed version number is below 8.3.10, or is between 9.0 and 9.5 (for example, 9.4.x, 9.3.x, 9.2.x, 9.1.x, 9.0.x)
-
Verify access to the proxyPreviewAction featureAttempt to access or trigger the proxy preview functionality in Foxit (this is an internal function, so focus on version detection instead)Affected if The vulnerable proxyPreviewAction function exists in the installed version and could be triggered if the user processes a specially crafted PDF file
The system is affected if Foxit Reader version is below 9.5, or PhantomPDF version is below 8.3.10, or PhantomPDF version is 9.0 through 9.5.
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 data8.3.109.5
Update Foxit Reader to version 9.5 or later, and PhantomPDF to version 8.3.10/9.5 or later, to remediate the race condition vulnerability.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-20313 — 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-2018-20313 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data