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TI-2021-07832 Aliases CVE-2021-25741GHSA-f5f7-6478-qm6p

Symlink Exchange Can Allow Host Filesystem Access

Priority MEDIUM 51CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-552.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.07964 94th percentileScored 2026-11-07
Fix Partial k8s.io/kubernetes (Go): 1.19.15, 1.20.11, 1.21.5 +1Red Hat: 4 advisoriesRed Hat: 4 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
KubernetesKubernetesup to 1.19.14; up to 1.20.10; up to 1.21.4; up to 1.22.1—No fix listedCNA
—k8s.io/kubernetes (Go)before 1.19.151.19.15Patch availableGHSA-f5f7-6478-qm6p
—k8s.io/kubernetes (Go)1.20.0 to before 1.20.111.20.11Patch availableGHSA-f5f7-6478-qm6p
—k8s.io/kubernetes (Go)1.21.0 to before 1.21.51.21.5Patch availableGHSA-f5f7-6478-qm6p
—k8s.io/kubernetes (Go)1.22.0 to before 1.22.21.22.2Patch availableGHSA-f5f7-6478-qm6p
  • Kubernetes VendorKubernetes Affected up to 1.19.14; up to 1.20.10; up to 1.21.4; up to 1.22.1 Fixed in — No fix listed CNA
  • k8s.io/kubernetes (Go) Vendor— Affected before 1.19.15 Fixed in 1.19.15 Patch available GHSA-f5f7-6478-qm6p
  • k8s.io/kubernetes (Go) Vendor— Affected 1.20.0 to before 1.20.11 Fixed in 1.20.11 Patch available GHSA-f5f7-6478-qm6p
  • k8s.io/kubernetes (Go) Vendor— Affected 1.21.0 to before 1.21.5 Fixed in 1.21.5 Patch available GHSA-f5f7-6478-qm6p
  • k8s.io/kubernetes (Go) Vendor— Affected 1.22.0 to before 1.22.2 Fixed in 1.22.2 Patch available GHSA-f5f7-6478-qm6p

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*up to 1.19.14; 1.20.0 – 1.20.10; 1.21.0 – 1.21.4; 1.22.0 – 1.22.1VulnerableKubernetes
  • cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* Versions up to 1.19.14; 1.20.0 – 1.20.10; 1.21.0 – 1.21.4; 1.22.0 – 1.22.1 Vulnerable ·Kubernetes

Remediation

  • Fix · GHSA-f5f7-6478-qm6p k8s.io/kubernetes (Go) Fixed in 1.19.15 Advisory →
  • Fix · GHSA-f5f7-6478-qm6p k8s.io/kubernetes (Go) Fixed in 1.20.11 Advisory →
  • Fix · GHSA-f5f7-6478-qm6p k8s.io/kubernetes (Go) Fixed in 1.21.5 Advisory →
  • Fix · GHSA-f5f7-6478-qm6p k8s.io/kubernetes (Go) Fixed in 1.22.2 Advisory →

Red Hat 4 advisories

  • RHSA-2021:3646 Released 2021-09-30 · Red Hat rating Important
    OpenShift Container Platform 3.11.524 security and bug fix update
    • Red Hat OpenShift Container Platform 3.11 atomic-openshift-3.11.524-1.git.0.2dffce7.el7, atomic-openshift-clients-3.11.524-1.git.0.2dffce7.el7, atomic-openshift-clients-redistributable-3.11.524-1.git.0.2dffce7.el7 +10
  • RHSA-2021:3635 Released 2021-09-29 · Red Hat rating Important
    OpenShift Container Platform 4.7.32 packages and security update
    • Red Hat OpenShift Container Platform 4.7 openshift-4.7.0-202109172126.p0.git.bbbc079.assembly.stream.el7, openshift-4.7.0-202109172126.p0.git.bbbc079.assembly.stream.el8, openshift-hyperkube-4.7.0-202109172126.p0.git.bbbc079.assembly.stream.el7 +1
  • RHSA-2021:3642 Released 2021-09-29 · Red Hat rating Important
    OpenShift Container Platform 4.6.46 security update
    • Red Hat OpenShift Container Platform 4.6 openshift-4.6.0-202109180038.p0.git.d5ed12c.assembly.stream.el7, openshift-4.6.0-202109180038.p0.git.d5ed12c.assembly.stream.el8, openshift-hyperkube-4.6.0-202109180038.p0.git.d5ed12c.assembly.stream.el7 +1
Show 1 more Red Hat advisories
  • RHSA-2021:3631 Released 2021-09-28 · Red Hat rating Important
    OpenShift Container Platform 4.8.13 security update
    • Red Hat OpenShift Container Platform 4.8 openshift-4.8.0-202109180335.p0.git.a620f50.assembly.stream.el7, openshift-4.8.0-202109180335.p0.git.a620f50.assembly.stream.el8, openshift-hyperkube-4.8.0-202109180335.p0.git.a620f50.assembly.stream.el7 +1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 3.11Fixed RHSA-2021:3646
Red Hat OpenShift Container Platform 4.6Fixed RHSA-2021:3642
Red Hat OpenShift Container Platform 4.7Fixed RHSA-2021:3635
Red Hat OpenShift Container Platform 4.8Fixed RHSA-2021:3631
Not affected: 3 products
  • Red Hat OpenShift Container Platform 3.11
  • Red Hat OpenShift Container Platform 4.6
  • Red Hat OpenShift Container Platform 4.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-25741
  2. 2026-10-03 Alias added: GHSA-f5f7-6478-qm6p

References

Advisory 3

Other 4

  • TI-2018-16130 Improper privilege management in Kubernetes CVSS 3.0CRITICAL 9.8
  • TI-2019-08418 Kubernetes kubelet exposes /debug/pprof info on healthz port CVSS 3.1HIGH 8.2
  • TI-2023-05086 Kubernetes - Windows nodes - Insufficient input sanitization in in-tree storage plugin leads to privilege escalation CVSS 3.1HIGH 8.8
  • TI-2023-03433 Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation CVSS 3.1HIGH 8.8
  • TI-2023-02285 Bypass of seccomp profile enforcement CVSS 3.1MEDIUM 5.5
  • TI-2017-14755 Link following in Kubernetes CVSS 3.0CRITICAL 9.6
See all 55 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences