CVE-2020-27814Public exploit

Code execution via undersized encoder buffer

Published Jan 25, 2021 · Updated Aug 4, 2024

Heap-buffer overflow in OpenJPEG before 2.4.0 allows attackers to execute code with the application's privileges via a crafted PNG file. During encoding, opj_tcd_code_block_enc_allocate_data reserves too little output space, and opj_mqc_byteout writes past the heap buffer while flushing compressed data. A victim must process the file with the encoder; successful exploitation can crash the application or run code with that application's privileges.

CVSS severity7.8
High
EPSS probability2.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in OpenJPEG before 2.4.0 allows attackers to execute code with the application's privileges via a crafted PNG file. During encoding, opj_tcd_code_block_enc_allocate_data reserves too little output space, and opj_mqc_byteout writes past the heap buffer while flushing compressed data. A victim must process the file with the encoder; successful exploitation can crash the application or run code with that application's privileges.

The record

CVE
CVE-2020-27814
Published
Jan 25, 2021
Updated
Aug 4, 2024
Vendor
Université catholique de Louvain
Product
OpenJPEG
Classifications
CWE-122, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 25, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=before openjpeg 2.4.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Université catholique de Louvain · OpenJPEGversion=before openjpeg 2.4.0

Published CVSS scores

7.8CanonicalCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-122Heap-based Buffer Overflow
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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