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FfmpegApplication

CVE-2020-24020

HIGH · 8.8 CVSS v3.1 Published 2021-05-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
Buffer Overflow vulnerability in FFMpeg 4.2.3 in dnn_execute_layer_pad in libavfilter/dnn/dnn_backend_native_layer_pad.c due to a call to memcpy without length checks, which could let a remote malicious user execute arbitrary code.

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

A buffer overflow vulnerability exists in FFMpeg 4.2.3 within the dnn_execute_layer_pad function in libavfilter/dnn/dnn_backend_native_layer_pad.c. The vulnerability stems from a memcpy call that lacks proper length validation, allowing a remote attacker to overwrite memory boundaries and potentially execute arbitrary code.

MitigationUpdate FFMpeg to a version beyond 4.2.3 that includes proper bounds checking on the memcpy operation in the DNN backend pad layer, or apply a patch that adds length validation before the memcpy call.

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
FfmpegApplication
Affected:= 4.2.3

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
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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 installed FFMpeg version
    Run 'ffmpeg -version' and look for the version number in the output
    Affected if The version displayed is exactly 4.2.3
  2. Locate the vulnerable DNN component
    Check if the file libavfilter/dnn/dnn_backend_native_layer_pad.c exists in the FFMpeg installation directory or source tree
    Affected if The file exists and is from FFMpeg 4.2.3
  3. Verify DNN filter usage in processing pipeline
    Inspect any FFMpeg commands or configurations that invoke DNN-based filters, particularly those that may use the pad layer operation in neural network processing
    Affected if DNN filters are actively used with pad operations on input media

The environment is affected only if FFMpeg version 4.2.3 is installed AND the DNN backend with pad layer processing is being utilized, as the buffer overflow only triggers during DNN pad layer execution.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update FFMpeg to a version beyond 4.2.3 that includes proper bounds checking on the memcpy operation in the DNN backend pad layer, or apply a patch that adds length validation before the memcpy call.

Fix this in Ffmpeg 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-2020-24020 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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