CVE-2018-18456
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 · uneditedThe function Object::isName() in Object.h (called from Gfx::opSetFillColorN) in Xpdf 4.00 allows remote attackers to cause a denial of service (stack-based buffer over-read) via a crafted pdf file, as demonstrated by pdftoppm.
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 stack-based buffer over-read vulnerability exists in Xpdf 4.00's Object::isName() function in Object.h, which is invoked by Gfx::opSetFillColorN. Processing a crafted PDF file with utilities like pdftoppm triggers the over-read, causing a denial of service.
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= 4.00CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 if Xpdf is installedRun 'which pdftoppm' or 'which xpdf' to locate Xpdf binaries, or list files in common Xpdf binary directories like /usr/bin/ or /usr/local/bin/Affected if No Xpdf binaries are found - not vulnerable since Xpdf is not present
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Identify the installed Xpdf versionRun 'pdftoppm -v' or 'xpdf -v' to display the version numberAffected if Version is exactly 4.00 - this is the affected version
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Verify the pdftoppm utility is availableConfirm the pdftoppm binary exists on the system using 'ls -la' on the path found in step 1, or try running 'pdftoppm -h'Affected if pdftoppm is present and version is 4.00 - the specific utility mentioned in the CVE is accessible and vulnerable
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Check for the vulnerable Object.h fileLocate the Xpdf installation directory and verify the presence of Object.h containing the isName() function (if source or development files are available)Affected if The Object.h file with the isName() function exists in an Xpdf 4.00 installation - confirms the vulnerable code path is present
You are affected if Xpdf version 4.00 is installed and the pdftoppm utility (or other Xpdf PDF processing tools) is accessible on your system.
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 Xpdf to the latest patched version, or if unavailable, avoid processing untrusted PDF files with vulnerable Xpdf utilities until a patch is released.
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-18456 — 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-2018-18456 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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