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LibavApplication

CVE-2017-18243

MEDIUM · 6.5 CVSS v3.0 Published 2018-03-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable 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 unpack_parse_unit function in libavcodec/dirac_parser.c in Libav 12.2 allows remote attackers to cause a denial of service (segmentation fault) via a crafted 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 segmentation fault vulnerability exists in Libav 12.2 within the dirac_parser.c file's unpack_parse_unit function. The vulnerability is triggered when processing a specially crafted Dirac file, causing a denial of service via a crash. This is a parsing logic flaw, likely a missing bounds or null pointer check.

MitigationAvoid processing untrusted Dirac files with vulnerable Libav installations. Update to patched Libav versions when available. If Libav is used in a server context, implement file validation before processing.

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
LibavApplication
Affected:= 12.2

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
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 checks

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

  1. Check installed Libav version
    Run 'avconv -version' or 'avplay -version' to display the Libav version number
    Affected if Version displayed is exactly 12.2
  2. Verify Dirac demuxer support is enabled
    Run 'avconv -formats 2>/dev/null | grep -i dirac' or check Libav build configuration for Dirac demuxer
    Affected if Dirac demuxer is listed as supported (flags contain 'D' for demux) in the available formats
  3. Identify if Dirac files are processed in your environment
    Search application logs, file processing records, or media asset management systems for .drc, .dirac, or .vc2 file extensions
    Affected if Your system processes or has processed Dirac format files using the vulnerable Libav installation

You are affected if Libav version 12.2 is installed AND the Dirac demuxer is enabled AND your environment processes Dirac files, which would trigger the vulnerable unpack_parse_unit function in dirac_parser.c.

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

Avoid processing untrusted Dirac files with vulnerable Libav installations. Update to patched Libav versions when available. If Libav is used in a server context, implement file validation before processing.

Fix this in Libav Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2017-18243 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