CVE-2017-13726
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 · uneditedThere is a reachable assertion abort in the function TIFFWriteDirectorySec() in LibTIFF 4.0.8, related to tif_dirwrite.c and a SubIFD tag. A crafted input will lead to a remote denial of service attack.
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 · moderate confidenceA reachable assertion abort exists in LibTIFF 4.0.8's TIFFWriteDirectorySec() function in tif_dirwrite.c when processing a crafted TIFF file containing a specially crafted SubIFD tag. The vulnerability allows a remote attacker to cause a denial of service via assertion failure.
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= 4.0.8CVSS 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
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/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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Identify installed LibTIFF versionRun 'tiffinfo -version' or check your system's package manager for libtiff version (e.g., 'dpkg -l libtiff' on Debian, 'rpm -q libtiff' on RHEL)Affected if The version shown is exactly 4.0.8
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Locate libtiff shared libraryFind the libtiff library file (typically /usr/lib/x86_64-linux-gnu/libtiff.so.5 or similar path) and run 'strings' or check metadata for version infoAffected if Library version resolves to 4.0.8
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Identify TIFF processing applicationsCheck for installed tools that depend on libtiff: 'which tiffinfo tiff2pdf tiffcp tiff2ps' or search for binaries linked against libtiff using 'ldd' or 'objdump'Affected if Any TIFF utility tools are present and linked to libtiff 4.0.8
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Determine if custom code uses vulnerable functionSearch source code repositories for calls to TIFFWriteDirectorySec() or TIFFWriteDirectory() functions, or grep for 'tif_dirwrite.c' in any custom imaging softwareAffected if Custom code directly invokes the TIFFWriteDirectorySec() or TIFFWriteDirectory() function on untrusted TIFF input
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Assess TIFF file processing exposureReview any web services, file upload handlers, or automated processing pipelines that accept TIFF files as inputAffected if Your system accepts or processes TIFF files from untrusted sources without prior validation
You are affected if LibTIFF version 4.0.8 is installed AND your environment processes TIFF files containing SubIFD tags, whether through standard tools or custom code that calls the vulnerable TIFFWriteDirectorySec() function.
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 LibTIFF to the latest patched version (post-4.0.8) and implement input validation for TIFF files before processing to reject files with malformed SubIFD tags.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-13726 — 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-2017-13726 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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