CVE-2020-23705Public exploitNetwork attack vector

Codec crash via oversized Huffman table copy

Published Jul 15, 2021 · Updated Aug 4, 2024

Global buffer overflow in ffjpeg through 2020-06-22 allows attackers to crash the codec by processing a crafted JPEG file. In jfif_encode, memcpy reads 272 bytes from the 178-byte STD_HUFTAB_LUMIN_AC global Huffman table, crossing its boundary. Exploitation requires attacker-supplied image input to be processed and is limited to an availability-impacting crash.

CVSS severity6.5
Medium
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Global buffer overflow in ffjpeg through 2020-06-22 allows attackers to crash the codec by processing a crafted JPEG file. In jfif_encode, memcpy reads 272 bytes from the 178-byte STD_HUFTAB_LUMIN_AC global Huffman table, crossing its boundary. Exploitation requires attacker-supplied image input to be processed and is limited to an availability-impacting crash.

The record

CVE
CVE-2020-23705
Published
Jul 15, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 15, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NVDAV: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1204.002User Execution: Malicious 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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