CVE-2011-3945
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 decode_frame function in the KVG1 decoder (kgv1dec.c) in libavcodec in FFmpeg 0.7.x before 0.7.12 and 0.8.x before 0.8.11, and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.5, and 0.8.x before 0.8.1, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted media 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 confidenceA memory corruption vulnerability exists in the KVG1 video decoder (kgv1dec.c) in FFmpeg and Libav. The decode_frame function fails to properly validate or handle crafted media files, allowing attackers to trigger a crash (denial of service) and potentially achieve arbitrary code execution via a specially malformed KVG1 stream.
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= 0.7= 0.7.1= 0.7.2= 0.7.3= 0.7.6= 0.7.7= 0.7.8= 0.7.9= 0.7.11= 0.8.0= 0.8.1= 0.8.2= 0.5= 0.5.1= 0.5.2= 0.5.3= 0.5.4= 0.5.5= 0.5.6= 0.5.7= 0.6= 0.6.1= 0.6.2= 0.6.3CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
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 multimedia frameworkRun 'ffmpeg -version' or 'avconv -version' (Libav uses avconv) to determine if either FFmpeg or Libav is installedAffected if No output indicates the software is not present
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Confirm exact version of FFmpegIf FFmpeg is present, run 'ffmpeg -version' and note the full version string (e.g., 0.7.3, 0.8.1)Affected if Version matches any of: 0.7, 0.7.1, 0.7.2, 0.7.3, 0.7.6, 0.7.7, 0.7.8, 0.7.9, 0.7.11, 0.8.0, 0.8.1, 0.8.2
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Confirm exact version of LibavIf avconv is present, run 'avconv -version' and note the full version stringAffected if Version matches any of: 0.5 through 0.5.7, 0.6 through 0.6.3
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Check if KVG1 decoder is availableRun 'ffmpeg -codecs' or 'avconv -codecs' and search for 'kgv1' or 'KVG1' in the output list of video decodersAffected if The KVG1 decoder appears in the available codecs list, indicating support was compiled in
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Check decoder configurationRun 'ffmpeg -h decoder=kgv1' or 'avconv -h decoder=kgv1' to confirm the decoder is functional and not explicitly disabledAffected if The decoder is present and enabled, allowing processing of KVG1 streams
User is affected if they have an affected FFmpeg or Libav version (0.7.x/0.8.x for FFmpeg, 0.5.x/0.6.x for Libav) AND the KVG1 decoder is available and enabled in their installation.
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 dataUpgrade FFmpeg to version 0.7.12 or later (0.8.x to 0.8.11 or later), or Libav to 0.5.9+, 0.6.6+, 0.7.5+, or 0.8.1+ respectively. If upgrading is not immediately feasible, restrict processing of untrusted KVG1 media files and disable the kgv1 decoder.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-3945 — 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-2011-3945 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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