CVE-2021-21285 Docker daemon crash during image pull of malicious image

What is CVE-2021-21285?

CVE-2021-21285 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 2 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

In Docker before versions 9.03.15, 20.10.3 there is a vulnerability in which pulling an intentionally malformed Docker image manifest crashes the dockerd daemon. Versions 20.10.3 and 19.03.15 contain patches that prevent the daemon from crashing.

Weakness: CWE-754, CWE-400

Which versions are affected by CVE-2021-21285?

4 open source packages ship an affected version, including github.com/moby/moby. It affects 3 products.

Products include Debian Debian Linux, Docker Docker, Netapp E-Series Santricity Os Controller.

How do I fix CVE-2021-21285?

Upgrade github.com/moby/moby to a fixed version for your release line: 19.3.15 or 20.10.3.

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-2021-21285 being exploited?

There is no known exploitation of CVE-2021-21285 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• 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 CLEANSTART-2026-TE15990, DEBIAN-CVE-2021-21285, GHSA-6fj5-m822-rqx8, UBUNTU-CVE-2021-21285.