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XpdfApplication · Xpdfreader

CVE-2018-18458

MEDIUM · 5.5 CVSS v3.0 Published 2018-10-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
58/100
Remediation priority · Elevated
No privileges

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 · unedited
The function DCTStream::decodeImage in Stream.cc in Xpdf 4.00 allows remote attackers to cause a denial of service (NULL pointer dereference) 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 confidence

A NULL pointer dereference vulnerability exists in Xpdf 4.00's DCTStream::decodeImage function in Stream.cc. Attackers can trigger this by providing a specially crafted PDF file, causing a denial of service when the PDF is processed by utilities like pdftoppm.

MitigationUpgrade to a patched version of Xpdf that addresses this NULL pointer dereference, or apply a code fix to add proper NULL pointer validation in the DCTStream::decodeImage function before dereferencing.

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
XpdfApplication
Affected:= 4.00

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Verify Xpdf is installed
    Run 'which pdftoppm' or 'which xpdf' to locate Xpdf utilities on the system
    Affected if Xpdf utilities are found on the system
  2. Identify installed Xpdf version
    Run 'pdftoppm -v' or check the application's version information via the package manager (e.g., 'dpkg -l | grep xpdf' or 'rpm -qa | grep xpdf')
    Affected if The installed version is exactly 4.00
  3. Confirm the DCTStream component exists
    Locate the Stream.cc source file or Stream.o object file in the Xpdf installation directory to verify the DCTStream::decodeImage function is present
    Affected if The DCTStream component with decodeImage function exists in the installation
  4. Determine if PDF processing utilities are accessible
    Check for the presence of pdftoppm, pdftocairo, or other PDF rendering utilities that use the DCTStream component
    Affected if pdftoppm or similar PDF-to-image conversion utilities are available and linked to the affected Xpdf library

The system is affected if Xpdf version 4.00 is installed and pdftoppm or related PDF processing utilities are available to process user-supplied PDF files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of Xpdf that addresses this NULL pointer dereference, or apply a code fix to add proper NULL pointer validation in the DCTStream::decodeImage function before dereferencing.

Fix this in Xpdf Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-18458 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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