// For flags

CVE-2021-25741

Symlink Exchange Can Allow Host Filesystem Access

Severity Score

8.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

2
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track*
*SSVC
Descriptions

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.

Se ha detectado un problema de seguridad en Kubernetes en el que un usuario puede ser capaz de crear un contenedor con montajes de volumen de sub-ruta para acceder a archivos y directorios fuera del volumen, incluso en el sistema de archivos del host

A flaw was found in kubernetes. An authorized user can exploit this by creating pods with crafted subpath volume mounts to access files and directories outside of the volume, including on the host node's filesystem.

Red Hat Advanced Cluster Management for Kubernetes 2.3.3 images Red Hat Advanced Cluster Management for Kubernetes provides the capabilities to address common challenges that administrators and site reliability engineers face as they work across a range of public and private cloud environments. Clusters and applications are all visible and managed from a single console—with security policy built in. This advisory contains the container images for Red Hat Advanced Cluster Management for Kubernetes, which fix several bugs and provide security updates. Issues addressed include denial of service, information leakage, integer overflow, and out of bounds read vulnerabilities.

*Credits: Fabricio Voznika & Mark Wolters
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track*
Exploitation
None
Automatable
No
Tech. Impact
Total
* Organization's Worst-case Scenario
Timeline
  • 2021-01-21 CVE Reserved
  • 2021-09-20 CVE Published
  • 2022-01-19 First Exploit
  • 2024-09-16 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-20: Improper Input Validation
  • CWE-59: Improper Link Resolution Before File Access ('Link Following')
  • CWE-552: Files or Directories Accessible to External Parties
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Kubernetes
Search vendor "Kubernetes"
Kubernetes
Search vendor "Kubernetes" for product "Kubernetes"
<= 1.19.14
Search vendor "Kubernetes" for product "Kubernetes" and version " <= 1.19.14"
-
Affected
Kubernetes
Search vendor "Kubernetes"
Kubernetes
Search vendor "Kubernetes" for product "Kubernetes"
>= 1.20.0 <= 1.20.10
Search vendor "Kubernetes" for product "Kubernetes" and version " >= 1.20.0 <= 1.20.10"
-
Affected
Kubernetes
Search vendor "Kubernetes"
Kubernetes
Search vendor "Kubernetes" for product "Kubernetes"
>= 1.21.0 <= 1.21.4
Search vendor "Kubernetes" for product "Kubernetes" and version " >= 1.21.0 <= 1.21.4"
-
Affected
Kubernetes
Search vendor "Kubernetes"
Kubernetes
Search vendor "Kubernetes" for product "Kubernetes"
>= 1.22.0 <= 1.22.1
Search vendor "Kubernetes" for product "Kubernetes" and version " >= 1.22.0 <= 1.22.1"
-
Affected