CVE-2021-20245 Denial of service in ImageMagick

What is CVE-2021-20245?

CVE-2021-20245 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 9 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

A flaw was found in ImageMagick in coders/webp.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.

Weakness: CWE-369

Which versions are affected by CVE-2021-20245?

It affects 4 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Imagemagick Imagemagick, Redhat Enterprise Linux.

How do I fix CVE-2021-20245?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-20245 being exploited?

There is no known exploitation of CVE-2021-20245 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-20245, GHSA-pwcp-7wg2-65jc, JLSEC-2026-882, UBUNTU-CVE-2021-20245.