CVE-2012-2775
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 · uneditedUnspecified vulnerability in the read_var_block_data function in libavcodec/alsdec.c in FFmpeg before 0.11, and Libav 0.7.x before 0.7.7 and 0.8.x before 0.8.4, has unknown impact and attack vectors, related to a large order and an "out of array write in quant_cof."
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 confidenceBuffer overflow vulnerability in the ALS (Audio Lossless Coding) decoder in FFmpeg and Libav. The read_var_block_data function in libavcodec/alsdec.c does not properly validate the 'order' parameter, allowing a large order value to cause an out-of-bounds write beyond the allocated quant_cof array. This could enable arbitrary code execution via specially crafted ALS audio files.
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= 0.8= 0.8.1= 0.8.2= 0.8.3= 0.7= 0.7.1= 0.7.2= 0.7.3= 0.7.4= 0.7.5= 0.7.6<= 0.10.4= 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
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:N/C:C/I:C/A:C
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 the media library in useRun 'ffmpeg -version' or 'avconv -version' (Libav uses avconv) to determine which library is installedAffected if The output shows FFmpeg or Libav is present
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Check the installed versionFor FFmpeg: run 'ffmpeg -version' and note the version number. For Libav: run 'avconv -version' and note the version numberAffected if Version is FFmpeg <= 0.10.4, or FFmpeg 0.3.x/0.4.x series, or Libav 0.7.x/0.8.x series (specific versions listed in CVE
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Verify ALS decoder is availableRun 'ffmpeg -codecs 2>/dev/null | grep -i als' or 'avconv -codecs 2>/dev/null | grep -i als' to check if the ALS decoder is compiled inAffected if The ALS decoder is listed as available (decoders include D ALS)
You are affected if you are using FFmpeg <= 0.10.4 or FFmpeg 0.3.x/0.4.x, or Libav 0.7.x/0.8.x, AND the ALS decoder is enabled in your 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.
dbcve · scopedUpdate FFmpeg to version 0.11 or later, or Libav to version 0.7.7/0.8.4 or later. If updates are unavailable, disable ALS codec support in the affected libraries.
FFmpeg 0.11+ or Libav 0.7.7+/0.8.4+
- 1. Identify which library (FFmpeg or Libav) is in use in your system by running 'ffmpeg -version' or 'avconv -version'
- 2. For FFmpeg users: Upgrade to FFmpeg 0.11 or later (recommended: latest stable release)
- 3. For Libav users: If using 0.7.x line, upgrade to 0.7.7 or later; if using 0.8.x line, upgrade to 0.8.4 or later
- 4. Obtain the fixed version from your distribution's package manager or compile from source at ffmpeg.org or libav.org
- 5. Verify the upgrade was successful by checking the installed version: 'ffmpeg -version' or 'avconv -version'
- 6. Test that your media processing workflows function correctly with the new version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-2775 — 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-2012-2775 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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