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

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.

Published: 2021-02-02 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-21285 is rated Moderate Risk (59.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.29%). EPSS rose +2.94% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-21285

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.35% 3.29% +2.94%
2 2026-03-09 1.17% 0.35% -0.82%
3 2026-03-04 — 1.17% —

Full EPSS history (31 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21285

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-21285

GitHub Security Advisory for CVE-2021-21285

GHSA-6fj5-m822-rqx8 · Severity: medium · Ecosystem: go — moby docker daemon crash during image pull of malicious image

OS Trackers for CVE-2021-21285

vendor priority summary link
alpine medium CVE-2021-21285: 1 source package rows (docker); 17 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 10. https://security.alpinelinux.org/vuln/CVE-2021-21285
debian not yet assigned CVE-2021-21285 not yet assigned priority: Debian including 1 source packages (docker.io), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-21285
gentoo normal CVE-2021-21285: 1 GLSA(s) (202107-23), 1 atom(s) (app-emulation/docker); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-21285
redhat medium — https://access.redhat.com/security/cve/CVE-2021-21285
suse medium CVE-2021-21285 severity moderate: SUSE including 76 source package names (2.0.2-4.2.20:runc-1.0.0~rc93-1.14.2, containerd-1.3.9-5.29.3, …), 1105 product×package rows across 329 product lines (Container rancher/elemental-teal-iso/5.4, Container rancher/elemental-teal-rt/5.4, … (329 product lines)): Fixed 1105. https://www.suse.com/security/cve/CVE-2021-21285/
ubuntu medium CVE-2021-21285 medium priority: Ubuntu including 1 source packages (docker.io), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 9, released 3, DNE 1, ignored 1, needed 1, needs-triage 1. https://ubuntu.com/security/CVE-2021-21285

Affected software / configurations for CVE-2021-21285

Vendor Product Version Raw CPE
docker docker < 19.03.15 cpe:2.3:a:docker:docker:*:*:*:*:*:*:*:*
docker docker >= 20.0.0, < 20.10.3 cpe:2.3:a:docker:docker:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
netapp e-series_santricity_os_controller >= 11.0, <= 11.60.3 cpe:2.3:a:netapp:e-series_santricity_os_controller:*:*:*:*:*:*:*:*

References for CVE-2021-21285

cvelogic Threat Intelligence