CVE-2025-62878: Path Traversal Vulnerability

CVE-2025-62878 Overview

A path traversal vulnerability exists that allows a malicious user to manipulate the parameters.pathPattern to create PersistentVolumes in arbitrary locations on the host node. This security flaw could enable attackers to overwrite sensitive files or gain unauthorized access to unintended directories on the underlying host system.

Critical Impact

This vulnerability enables arbitrary file write and directory access on host nodes through PersistentVolume path manipulation, potentially leading to complete host compromise.

Affected Products

• Kubernetes environments using vulnerable PersistentVolume provisioners
• Container orchestration systems with dynamic volume provisioning
• Cloud-native storage solutions implementing pathPattern parameters

Discovery Timeline

• 2026-02-25 - CVE CVE-2025-62878 published to NVD
• 2026-02-25 - Last updated in NVD database

Technical Details for CVE-2025-62878

Vulnerability Analysis

This vulnerability is classified under CWE-23 (Relative Path Traversal), indicating that the affected component fails to properly sanitize user-supplied path patterns before using them to create PersistentVolumes. When a user provides a maliciously crafted pathPattern parameter containing directory traversal sequences, the system processes these sequences without validation, allowing the creation of storage volumes at arbitrary filesystem locations on the host node.

The network-accessible nature of this vulnerability means it can be exploited remotely by authenticated users with low privileges. The scope of exploitation extends beyond the vulnerable component itself, potentially affecting the confidentiality, integrity, and availability of the entire host system and any co-located workloads.

Root Cause

The root cause stems from insufficient input validation on the parameters.pathPattern field during PersistentVolume creation. The vulnerable component does not properly sanitize or restrict path traversal sequences such as ../ within the pathPattern parameter. This allows attackers to escape the intended storage directory and write to arbitrary locations on the host filesystem.

Attack Vector

An authenticated attacker with the ability to create PersistentVolumes can craft a malicious pathPattern containing path traversal sequences. When the volume provisioner processes this request, it creates the volume at the attacker-specified location on the host node rather than within the designated storage directory. This could allow:

• Overwriting critical system configuration files
• Injecting malicious content into executable directories
• Accessing sensitive data from other containers or the host system
• Establishing persistence mechanisms on the host node

The attack requires network access and low-level authentication, but no user interaction is needed for exploitation.

Detection Methods for CVE-2025-62878

Indicators of Compromise

• Unusual PersistentVolume creation requests containing ../ or similar path traversal sequences in pathPattern parameters
• PersistentVolumes mounted at unexpected host filesystem locations outside designated storage directories
• Unexpected file modifications in system directories coinciding with volume creation events
• Audit log entries showing volume provisioning with suspicious path specifications

Detection Strategies

• Implement monitoring for PersistentVolume and PersistentVolumeClaim creation events with pathPattern analysis
• Deploy admission controllers to validate and reject requests containing path traversal sequences
• Enable Kubernetes audit logging with focus on storage-related API calls
• Utilize runtime security tools to detect unexpected filesystem access patterns on host nodes

Monitoring Recommendations

• Configure alerting on PersistentVolume creation requests with path patterns containing traversal sequences
• Monitor for unexpected modifications to sensitive host directories
• Review storage provisioner logs for anomalous volume creation activities
• Implement file integrity monitoring on critical host system paths

How to Mitigate CVE-2025-62878

Immediate Actions Required

• Review and audit all existing PersistentVolumes for suspicious pathPattern configurations
• Implement admission controller policies to validate and sanitize pathPattern inputs
• Restrict PersistentVolume creation privileges to trusted administrators only
• Enable comprehensive audit logging for all storage-related operations

Patch Information

Security updates addressing this vulnerability should be applied as soon as they become available. For detailed patch information and vendor guidance, consult the GitHub Security Advisory GHSA-jr3w-9vfr-c746 and the SUSE Bug Report.

Workarounds

• Deploy OPA Gatekeeper or Kyverno policies to validate pathPattern inputs and reject requests containing path traversal sequences
• Implement RBAC restrictions to limit which users and service accounts can create PersistentVolumes
• Use read-only root filesystems where possible to limit the impact of unauthorized writes
• Isolate storage provisioners in dedicated namespaces with strict network policies

# Example: Restrict PersistentVolume creation with RBAC
# Create a ClusterRole that denies PV creation for non-admin users
kubectl create clusterrole pv-restricted \
  --verb=get,list,watch \
  --resource=persistentvolumes

# Apply admission controller policy to validate pathPattern
# Deploy OPA/Gatekeeper constraint to block path traversal patterns
kubectl apply -f - <<EOF
apiVersion: constraints.gatekeeper.sh/v1beta1
kind: PathTraversalCheck
metadata:
  name: block-path-traversal-pv
spec:
  match:
    kinds:
      - apiGroups: [""]
        kinds: ["PersistentVolume"]
EOF