CVE-2020-27842Public exploit

Application crash via unchecked precinct index

Published Jan 5, 2021 · Updated Aug 4, 2024

Out-of-bounds read in OpenJPEG before 2.4.0 allows local users to crash an encoding application with crafted image parameters. opj_t2_encode_packet uses a calculated precinct index to select a precinct tree without first ensuring that the index is below res->pw multiplied by res->ph, then passes the invalid tree to opj_tgt_reset. The demonstrated path requires small precincts, tile-part generation by component, and a nonzero grid offset; the reported consequence is an encoder abort with no data disclosure or code execution.

CVSS severity5.5
Medium
EPSS probability1.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in OpenJPEG before 2.4.0 allows local users to crash an encoding application with crafted image parameters. opj_t2_encode_packet uses a calculated precinct index to select a precinct tree without first ensuring that the index is below res->pw multiplied by res->ph, then passes the invalid tree to opj_tgt_reset. The demonstrated path requires small precincts, tile-part generation by component, and a nonzero grid offset; the reported consequence is an encoder abort with no data disclosure or code execution.

The record

CVE
CVE-2020-27842
Published
Jan 5, 2021
Updated
Aug 4, 2024
Vendor
Université catholique de Louvain
Product
OpenJPEG
Classifications
CWE-125
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 5, 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=openjpeg 2.4.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Université catholique de Louvain · OpenJPEGversion=openjpeg 2.4.0

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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-125Out-of-bounds Read

Public exploit references

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Technologies

Your stack

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Your stack

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