CVE-2012-2790
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 the "number of decoded samples in first sub-block in BGMC mode."
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 confidenceA vulnerability in the read_var_block_data function in libavcodec/alsdec.c in FFmpeg and Libav affects the decoding of ALS (Audio Lossless Coding) audio files. The issue involves improper handling of the number of decoded samples in the first sub-block when using BGMC (Block Gilbert-Moore Coding) mode, which can lead to memory corruption during audio file parsing.
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= 0.7.4= 0.7.5= 0.7.6= 0.8= 0.8.1= 0.8.2= 0.8.3<= 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 installed audio decoding libraryRun 'ffmpeg -version' or 'avconv -version' to determine if FFmpeg or Libav is installed. Also check for libavcodec packages via package manager (dpkg -l | grep -i libav or rpm -qa | grep -i libav).Affected if FFmpeg or Libav is installed and the version falls within the affected ranges (Libav 0.7-0.8.3, FFmpeg 0.3-0.10.4)
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Determine the exact version numberParse the version string from the -version output. For FFmpeg, look for versions <= 0.10.4 or any of 0.3.x through 0.4.x. For Libav, look for versions 0.7.x or 0.8.x up to 0.8.3.Affected if The installed version is one of the specific versions listed in the affected products range
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Verify ALS decoder module availabilityRun 'ffmpeg -codecs 2>/dev/null | grep -i als' or 'avconv -codecs 2>/dev/null | grep -i als' to check if the ALS (Audio Lossless Coding) decoder is compiled and available in the installation.Affected if The ALS decoder is present and the library version is within the affected range
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Check for ALS file processing activityReview application logs, proxy logs, or filesystem for recently accessed .als files. Use 'find / -name "*.als" 2>/dev/null' to locate ALS audio files, or check transcoding/job logs for ALS file inputs.Affected if ALS audio files from untrusted sources have been processed with an affected version of FFmpeg or Libav
You are affected if FFmpeg or Libav is installed with a version in the 0.7-0.8.3 (Libav) or 0.3-0.10.4 (FFmpeg) range, the ALS decoder is available, and untrusted ALS files have been decoded.
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 · scopedUpgrade to FFmpeg 0.11 or later, or Libav 0.7.7+/0.8.4+ to patch the vulnerability. Until then, exercise extreme caution when processing untrusted ALS audio files with affected versions.
FFmpeg: upgrade to 0.11 or later (latest stable recommended); Libav: upgrade to 0.7.7+/0.8.4+ or latest stable
- Identify which library (Libav or FFmpeg) is in use in your environment
- If using Libav: upgrade to version 0.7.7 or later (for 0.7.x branch), or 0.8.4 or later (for 0.8.x branch), or the latest stable release
- If using FFmpeg: upgrade to version 0.11 or later, or the latest stable release
- After upgrading, rebuild any applications that link against the library
- Test the upgraded library with your application to verify functionality
- Monitor for any regression issues and consult release notes if problems occur
Generated from the published advisory — verify against the referenced sources before acting.
- 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-2012-2790 — 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-2012-2790 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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