What is CVE-2021-20243?

CVE-2021-20243 is a medium-severity vulnerability in Imagemagick, classified under Divide By Zero. CVSS score: 5.5/10. Published 2021-03-09.

How severe is CVE-2021-20243?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Imagemagick

CVE-2021-20243

A flaw was found in ImageMagick in MagickCore/resize.c. An attacker who submits a crafted file that is processed by ImageMagick could trigger undefined behavior in the form of math division by zero. The highest threat from this vulnerability is to system availability.

Published 2021-03-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (63.4th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Imagemagick
Debian Linux — versions 9.0
Imagemagick — versions ImageMagick 7.0.10-62

Weakness classification (CWE)

CWE-369 — Divide By Zero

References

bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
github.com/ImageMagick/ImageMagick/pull/3193 (Patch, Third Party Advisory)
lists.debian.org/debian-lts-announce/2021/06/msg00000.html (mailing-list, Mailing List, Third Party Advisory)
lists.debian.org/debian-lts-announce/2023/05/msg00020.html (mailing-list)

Frequently asked questions

What is CVE-2021-20243?: CVE-2021-20243 is a medium-severity vulnerability in Imagemagick, classified under Divide By Zero. CVSS score: 5.5/10. Published 2021-03-09.
How severe is CVE-2021-20243?: Medium severity. CVSS v3 base score is 5.5 out of 10.