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Fencer Vulns
medium 5.3

CVE-2020-27534 json

Path Traversal in Moby builder

published 2020-12-30 5 y ago modified 2026-09-10 59 d ago also GHSA-6hwg-w5jg-9c6x , EUVD-2024-0274

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

util/binfmt_misc/check.go in Builder in Docker Engine before 19.03.9 calls os.OpenFile with a potentially unsafe qemu-check temporary pathname, constructed with an empty first argument in an ioutil.TempDir call.

Patch / fix

  • go github.com/moby/moby 19.03.9
  • go github.com/docker/docker 19.03.9
  • docker docker 19.03.9

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-27534 updated cvss 5.3

moby/buildkit: calls os.OpenFile with a potentially unsafe qemu-check temporary pathname

  • Red Hat OpenShift Container Platform 4 openshift4/ose-cli, openshift4/ose-tests, openshift4/ose-hypershift, openshift4/ose-kube-proxy, source-to-image-container, openshift4/ose-cli-artifacts, +3 more Red Hat Quay 3 quay-operator
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.77% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
go github.com/moby/moby
<19.03.9
19.03.9
go github.com/docker/docker
<19.03.9
19.03.9

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.