CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access
First published: Mon 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.
Credit: jordan@liggitt.net
| Affected Software | Affected Version | How to fix |
|---|---|---|
| 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 |
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Reference Links
- https://github.com/kubernetes/kubernetes/issues/104980
- https://groups.google.com/g/kubernetes-security-announce/c/nyfdhK24H7s
- https://security.netapp.com/advisory/ntap-20211008-0006/
- https://access.redhat.com/errata/RHSA-2021:3631
- https://access.redhat.com/security/cve/cve-2021-25741
- https://access.redhat.com/errata/RHSA-2021:3642
- https://access.redhat.com/errata/RHSA-2021:3635
- https://access.redhat.com/errata/RHSA-2021:3646
- https://bugzilla.redhat.com/show_bug.cgi?id=1993749
Frequently Asked Questions
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.
What is the severity of CVE-2021-25741?
The severity of CVE-2021-25741 is high, with a CVSS score of 8.1.
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.
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.
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.
- collector/nvd-index
- agent/type
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- agent/softwarecombine
- agent/weakness
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- alias/CVE-2021-25741
- agent/software-canonical-lookup
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- vendor/kubernetes
- canonical/kubernetes kubernetes
- version/kubernetes kubernetes/1.19.14
- version/kubernetes kubernetes/1.20.0
- version/kubernetes kubernetes/1.20.10
- version/kubernetes kubernetes/1.21.0
- version/kubernetes kubernetes/1.21.4
- version/kubernetes kubernetes/1.22.0
- version/kubernetes kubernetes/1.22.1
- package-manager/redhat