CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access

Published Aug 16, 2021
·
Updated

A security issue was discovered in Kubernetes where a user may be able to create a container with subpath volume mounts to access files & directories outside of the volume, including on the host filesystem.

Other sources

Symlink Exchange Can Allow Host Filesystem Access

Microsoft

Affected Software

16 affected componentsFixes available
redhat/kubernetes<1.22.2
1.22.2
redhat/kubernetes<1.21.5
1.21.5
redhat/kubernetes<1.20.11
1.20.11
redhat/kubernetes<1.19.15
1.19.15
Kubernetes kubernetes<=1.19.14
Kubernetes kubernetes>=1.20.0<=1.20.10
Kubernetes kubernetes>=1.21.0<=1.21.4
Kubernetes kubernetes>=1.22.0<=1.22.1
IBM Edge Application Manager<=4.5
Microsoft cm1 kubernetes-1.21.1 1.21.1-7
Microsoft cm1 kubernetes-1.19.13 1.19.13-5
Microsoft cm1 kubernetes-1.20.7 1.20.7-9
Microsoft cm1 kubernetes-1.21.2 1.21.2-7
Microsoft cm1 kubernetes-1.19.11 1.19.11-7
Microsoft cm1 kubernetes 1.21.2-7
Microsoft cm1 kubernetes-1.20.9 1.20.9-7

Event History

Sep 20, 2021
CVE Published
via MITRE·05:05 PM
Data Sourced
via MITRE·05:05 PM
DescriptionSeverityWeakness
Aug 20, 2025
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software
Oct 1, 2025
Data Sourced
via Microsoft·11:11 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·11:11 PM
Affected Software
Updated
via Microsoft·11:11 PM
DescriptionSeverity

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2021-25741?

CVE-2021-25741 is a security issue discovered in Kubernetes where a user may be able to create a container with subpath volume mounts to access files & directories outside of the volume, including on the host filesystem.

2

What is the severity of CVE-2021-25741?

The severity of CVE-2021-25741 is high, with a CVSS score of 8.1.

3

Which versions of Kubernetes are affected by CVE-2021-25741?

Kubernetes versions up to and including 1.22.1, 1.21.4, and 1.20.10 are affected by CVE-2021-25741.

4

How can I fix CVE-2021-25741?

To fix CVE-2021-25741, update your Kubernetes installation to version 1.22.2, 1.21.5, or 1.20.11, depending on your currently deployed version.

5

Where can I find more information about CVE-2021-25741?

You can find more information about CVE-2021-25741 in the GitHub issue and Red Hat security advisories linked in the references.

Contact

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