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Debian LinuxOperating system · Debian

CVE-2009-0385

HIGH · 9.3 CVSS v2.0 Published 2009-02-02
Fix available
A fix is available. Upgrade to 0.6.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Integer signedness error in the fourxm_read_header function in libavformat/4xm.c in FFmpeg before revision 16846 allows remote attackers to execute arbitrary code via a malformed 4X movie file with a large current_track value, which triggers a NULL pointer dereference.

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

Integer signedness error in the fourxm_read_header function in libavformat/4xm.c allows remote attackers to execute arbitrary code via a malformed 4X movie file containing a large current_track value, triggering a NULL pointer dereference.

MitigationUpgrade to FFmpeg revision 16846 or later, or apply the specific signedness fix to the current_track variable handling in the fourxm_read_header function to ensure proper bounds checking before pointer dereference.

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
Debian LinuxOperating system
Affected:= 4.0= 5.0= 6.0
Ubuntu LinuxOperating system
Affected:= 7.10= 8.04= 8.10
FedoraOperating system
Affected:= 9= 10
FfmpegApplication
Affected:< 0.6.3

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
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:M/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 checks

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

  1. Check if FFmpeg is installed
    Run 'ffmpeg -version' or 'ffmpeg -formats' to list installed FFmpeg binaries and their configurations
    Affected if FFmpeg is installed and the 4xm format is listed in the supported formats
  2. Identify the installed FFmpeg version
    Run 'ffmpeg -version' and note the version number displayed (e.g., 0.6, 0.6.2, etc.)
    Affected if The version is earlier than 0.6.3 (such as 0.5.x, 0.6, 0.6.1, 0.6.2) or if the version cannot be determined but the package is from Debian 4.0/5.0/6.0, Ubuntu 7.10/8.04/8.10, or Fedora 9/10
  3. Check if libavformat is present and its version
    Run 'avconv -version' or check the libavformat library file (typically libavformat.so or libavformat.so.52/53 in /usr/lib)
    Affected if libavformat version is earlier than what ships with FFmpeg 0.6.3, or the shared library is from an affected distribution package
  4. Verify 4xm format decoder availability
    Run 'ffmpeg -formats 2>&1 | grep -i 4xm' or 'ffmpeg -codecs 2>&1 | grep -i 4xm' to see if the 4xm decoder is compiled in
    Affected if The 4xm decoder is enabled in the build - the vulnerability only triggers when parsing a 4X movie file using this decoder
  5. Inspect the vulnerable source code if accessible
    If libavformat source is available, check libavformat/4xm.c for the fourxm_read_header function and verify if the current_track variable has proper bounds checking before use (look for signedness fix applied to the variable)
    Affected if The source code contains the vulnerable implementation without proper signedness handling on the current_track variable, allowing large values to cause NULL pointer dereference

A user is affected if they have FFmpeg or libavformat installed with a version earlier than 0.6.3 and the 4xm format decoder is enabled, enabling parsing of malicious 4X movie files to trigger the NULL pointer dereference.

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.

dbcve · scoped
Upgrade available Upgrade to 0.6.3 or later
Fixed in 0.6.3
Interim mitigation

Upgrade to FFmpeg revision 16846 or later, or apply the specific signedness fix to the current_track variable handling in the fourxm_read_header function to ensure proper bounds checking before pointer dereference.

Recommended fix High confidence

FFmpeg 0.6.3 or later (fixed in revision 16846)

  1. Upgrade FFmpeg to version 0.6.3 or later to obtain the fix for the integer signedness error in libavformat/4xm.c (revision 16846)
  2. Verify the upgrade by running 'ffmpeg -version' to confirm the installed version
  3. Test with a 4X movie file to ensure the library handles malformed input safely

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2009-0385 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