CVE-2020-27824

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-05-13 · updated 2026-06-17
Weakness: CWE-20

Description

A flaw was found in OpenJPEG’s encoder in the opj_dwt_calc_explicit_stepsizes() function. This flaw allows an attacker who can supply crafted input to decomposition levels to cause a buffer overflow. The highest threat from this vulnerability is to system availability.

Affected products

Debian Linux: 9.0, 10.0
Fedoraproject Fedora: 32, 33
Red Hat Enterprise Linux: 8.0
uclouvain openjpeg: before 2.4.0 — fixed in 2.4.0

How to fix

Upgrade to a fixed version: uclouvain openjpeg 2.4.0. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1905723
https://lists.debian.org/debian-lts-announce/2021/02/msg00011.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQR4EWRFFZQDMFPZKFZ6I3USLMW6TKTP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WJUPGIZE6A4O52EBOF75MCXJOL6MUCRV/
https://www.debian.org/security/2021/dsa-4882
https://www.oracle.com/security-alerts/cpuoct2021.html
https://bugzilla.redhat.com/show_bug.cgi?id=1905723
https://lists.debian.org/debian-lts-announce/2021/02/msg00011.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQR4EWRFFZQDMFPZKFZ6I3USLMW6TKTP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WJUPGIZE6A4O52EBOF75MCXJOL6MUCRV/
https://www.debian.org/security/2021/dsa-4882
https://www.oracle.com/security-alerts/cpuoct2021.html

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