CVE-2011-3949
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 dirac_unpack_idwt_params function in libavcodec/diracdec.c in FFmpeg before 0.10 allows remote attackers to have an unspecified impact via crafted Dirac data.
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 confidenceThe dirac_unpack_idwt_params function in libavcodec/diracdec.c in FFmpeg before version 0.10 contains a vulnerability in parsing Dirac video codec parameters. Crafted Dirac data with malformed parameters can trigger unspecified memory corruption, likely a buffer overflow or out-of-bounds read/write condition during the inverse discrete wavelet transform (IDWT) parameter unpacking process.
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<= 0.9.1= 0.3= 0.3.1= 0.3.2= 0.3.3= 0.3.4= 0.4.0= 0.4.2= 0.4.3= 0.4.4= 0.4.5= 0.4.6CVSS 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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Check if FFmpeg is installedRun `ffmpeg -version` or check your package manager for installed ffmpeg packagesAffected if FFmpeg is not installed means not affected
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Determine the installed FFmpeg versionParse the output of `ffmpeg -version` to extract the version number (e.g., 0.9.1, 0.4.6, etc.)Affected if Version matches <= 0.9.1 or equals any of: 0.3, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.4.0, 0.4.2, 0.4.3, 0.4.4, 0.4.5, 0.4.6
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Verify Dirac codec support is availableRun `ffmpeg -codecs 2>&1 | grep -i dirac` to list Dirac decoder capabilitiesAffected if Dirac decoder (D) is listed in the output indicates the vulnerable code path exists
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Confirm the libavcodec/diracdec.c component is presentCheck for the existence of libavcodec/diracdec.c in the FFmpeg library directory or verify via `ffmpeg -h decoder=dirac`Affected if The Dirac decoder is accessible and the library file exists means the vulnerability is present if version is affected
You are affected if FFmpeg version is 0.9.1 or earlier, or matches any version from 0.3 to 0.4.6, AND Dirac codec support is enabled in your FFmpeg build.
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 0.10 or later to obtain the patched libavcodec/diracdec.c. If upgrading is not feasible, disable Dirac codec support in FFmpeg or implement input validation to reject malformed Dirac streams before processing.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-3949 — 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-2011-3949 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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- Version or environment caveats, and links to real fixes
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