CVE-2021-25741: K8s.io/kubernetes Files Or Directories Accessible To Vulnerability
HIGHCVE-2021-25741 is a HIGH (CVSS 8.1) files or directories accessible to vulnerability (CWE-552: Files or Directories Accessible to External Parties) affecting K8s.io/kubernetes libraries in the Go ecosystem. The issue involves files or directories accessible to external parties in kubernetes. Remediation is available by upgrading affected packages to version 1.19.15, 1.20.11, 1.21.5, 1.22.2.
CVE-2021-25741 at a Glance
Security Impact
CVSS: 8.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).
How to Fix CVE-2021-25741
To remediate this vulnerability, upgrade all affected K8s.io/kubernetes dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade k8s.io/kubernetes to 1.19.15Upgrade k8s.io/kubernetes to 1.20.11Upgrade k8s.io/kubernetes to 1.21.5Upgrade k8s.io/kubernetes to 1.22.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for k8s.io/kubernetesHow to Check if You Are Affected
To determine whether your application is affected by CVE-2021-25741, inspect your project dependencies for K8s.io/kubernetes:
inspect dependencies for k8s.io/kubernetesAnalyze the terminal output to locate any version of K8s.io/kubernetes in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.19.15), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-552: Files or Directories Accessible to External Parties, where the product makes files or directories accessible to unauthorized actors, even though they should not be. In K8s.io/kubernetes, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-25741 Affected K8s.io/kubernetes Versions
4 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
k8s.io/kubernetes
|
Go |
< 1.19.15
|
1.19.15
|
|
k8s.io/kubernetes
|
Go |
≥ 1.20.0
< 1.20.11
|
1.20.11
|
|
k8s.io/kubernetes
|
Go |
≥ 1.21.0
< 1.21.5
|
1.21.5
|
|
k8s.io/kubernetes
|
Go |
≥ 1.22.0
< 1.22.2
|
1.22.2
|
References
Frequently Asked Questions
What is CVE-2021-25741?
Which K8s.io/kubernetes versions are affected?
What version fixes CVE-2021-25741?
Is k8s.io/kubernetes affected?
What is the CVSS score of CVE-2021-25741?
What CWE is associated with CVE-2021-25741?
How can I check Go dependencies for CVE-2021-25741?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-f5f7-6478-qm6p",
"modified" : "2021-11-01T17:26:17Z",
"published" : "2021-11-01T17:32:28Z",
"aliases" : [ "CVE-2021-25741" ],
"summary" : "Files or Directories Accessible to External Parties in kubernetes",
"details" : "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.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "k8s.io/kubernetes"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.19.15"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "k8s.io/kubernetes"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.20.0"
}, {
"fixed" : "1.20.11"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "k8s.io/kubernetes"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.21.0"
}, {
"fixed" : "1.21.5"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "k8s.io/kubernetes"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.22.0"
}, {
"fixed" : "1.22.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/bottlerocket-os/bottlerocket/security/advisories/GHSA-f5f7-6478-qm6p"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-25741"
}, {
"type" : "WEB",
"url" : "https://github.com/kubernetes/kubernetes/issues/104980"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/kubernetes/kubernetes"
}, {
"type" : "WEB",
"url" : "https://groups.google.com/g/kubernetes-security-announce/c/nyfdhK24H7s"
}, {
"type" : "WEB",
"url" : "https://security.netapp.com/advisory/ntap-20211008-0006"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-20", "CWE-552" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2021-11-01T17:26:17Z",
"nvd_published_at" : "2021-09-20T17:15:00Z"
}
}