CVE-2020-23851Public exploit

Decoder crash via unchecked YUV buffer index

Published May 18, 2021 · Updated Aug 4, 2024

Stack-based buffer overflow in ffjpeg through 2020-07-02 allows local users to crash the decoder via a malicious JPEG image. In jfif_decode, dimensions derived from JPEG data select an element beyond the three-pointer yuv_datbuf array before the pointer is dereferenced. Successful exploitation requires a user to pass the crafted file to ffjpeg for decoding and terminates that process with a segmentation fault.

CVSS severity5.5
Medium
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in ffjpeg through 2020-07-02 allows local users to crash the decoder via a malicious JPEG image. In jfif_decode, dimensions derived from JPEG data select an element beyond the three-pointer yuv_datbuf array before the pointer is dereferenced. Successful exploitation requires a user to pass the crafted file to ffjpeg for decoding and terminates that process with a segmentation fault.

The record

CVE
CVE-2020-23851
Published
May 18, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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