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FfmpegApplication

CVE-2016-6881

MEDIUM · 5.5 CVSS v3.0 Published 2016-12-23
Fix available
A fix is available. Upgrade to after 3.1.2 or later.
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 zlib_refill function in libavformat/swfdec.c in FFmpeg before 3.1.3 allows remote attackers to cause an infinite loop denial of service via a crafted SWF file.

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 vulnerability exists in FFmpeg's SWF (Shockwave Flash) file parser where the zlib_refill function in libavformat/swfdec.c enters an infinite loop when processing a crafted malicious SWF file. This leads to denial of service as the affected process becomes unresponsive while stuck in the loop.

MitigationUpgrade to FFmpeg version 3.1.3 or later. Until patched, avoid processing SWF files from untrusted sources.

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
FfmpegApplication
Affected:<= 3.1.2

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. Check installed FFmpeg version
    Run 'ffmpeg -version' and examine the version number in the output
    Affected if The version displayed is 3.1.2 or lower
  2. Verify SWF demuxer is available
    Run 'ffmpeg -formats 2>/dev/null | grep -i swf' or 'ffmpeg -demuxers 2>/dev/null | grep -i swf' to check if SWF demuxer is compiled into the build
    Affected if The SWF demuxer is listed as available (the vulnerability only applies when this component is present)
  3. Confirm libavformat/swfdec.c is in use
    Check if the file libavformat/swfdec.c exists in the FFmpeg installation directory (commonly found in /usr/lib/ffmpeg or /usr/local/lib or check build with 'ffmpeg -version 2>&1 | grep -i config' to see build configuration)
    Affected if The SWF parser component (swfdec.c) is present in the installation
  4. Identify active SWF processing
    Inspect running processes or scheduled tasks for FFmpeg commands that process .swf files (search process list for ffmpeg with .swf input files, or check logs for SWF file handling)
    Affected if FFmpeg is actively processing or scheduled to process SWF files from any source

User is affected if FFmpeg version is 3.1.2 or lower, the SWF demuxer is enabled in the build, and the system processes or may process SWF files using this FFmpeg installation.

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
Upgrade available Upgrade to a release after 3.1.2
Interim mitigation

Upgrade to FFmpeg version 3.1.3 or later. Until patched, avoid processing SWF files from untrusted sources.

Fix this in Ffmpeg Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

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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-2016-6881 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