EUVD-2026-5419: Comprehensive Technical Analysis

n8n Workflow Automation Platform - File Access Control Vulnerability

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1. VULNERABILITY ASSESSMENT AND SEVERITY EVALUATION

Severity Classification

CVSS 4.0 Base Score: 9.4 (CRITICAL)

This vulnerability represents a critical security flaw in the n8n workflow automation platform with the following characteristics:

CVSS 4.0 Vector Analysis

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Attack Vector Breakdown:

• Attack Vector (AV:N): Network-exploitable, requiring no physical or local access
• Attack Complexity (AC:L): Low complexity - no specialized conditions required
• Attack Requirements (AT:N): No additional attack requirements
• Privileges Required (PR:L): Low privileges - only authenticated user access needed
• User Interaction (UI:N): No user interaction required for exploitation
• Vulnerable System Impact: High across all CIA triad components (Confidentiality, Integrity, Availability)
• Subsequent System Impact: High across all components, indicating lateral movement potential

Risk Assessment

The 9.4 CVSS score places this vulnerability in the CRITICAL category, justified by:

1. Complete System Compromise: Ability to read sensitive files enables full account takeover
2. Privilege Escalation Path: Low-privileged users can access administrative credentials
3. Lateral Movement Capability: Subsequent system impacts rated HIGH indicate potential for broader infrastructure compromise
4. Minimal Attack Barriers: Low complexity and no user interaction required
5. Multi-tenant Risk: In shared hosting environments, cross-tenant data exposure is possible

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2. POTENTIAL ATTACK VECTORS AND EXPLOITATION METHODS

Primary Attack Vector: Workflow-Based File Access Bypass

Attack Chain:

[Authenticated User] → [Create/Modify Workflow] → [Exploit File Access Controls] 
→ [Read Sensitive Files] → [Extract Credentials] → [Account Takeover]

Exploitation Methodology

Phase 1: Initial Access

• Attacker obtains legitimate low-privileged credentials (workflow creator/editor role)
• Access can be obtained through:
  • Compromised employee accounts
  • Insider threats
  • Social engineering
  • Credential stuffing attacks

Phase 2: Vulnerability Exploitation

The vulnerability likely exists in one or more of these areas:

1. Path Traversal in Workflow Nodes

   • File read operations in workflow nodes may lack proper path sanitization
   • Attackers can use ../ sequences to escape intended directories
   • Example payload: ../../../../etc/passwd or ../../../../app/config/.env

2. Insufficient Access Control Validation

   • Workflow execution context may inherit excessive file system permissions
   • Missing checks on file paths before read operations
   • Inadequate sandboxing of workflow execution environment

3. Configuration File Exposure

   • Target files likely include:
     • .env files containing database credentials
     • config.json or similar configuration files
     • JWT signing keys
     • API tokens and secrets
     • Database connection strings
     • OAuth client secrets

Phase 3: Credential Extraction

Attackers target specific files:

/app/.env
/app/config/database.json
/root/.n8n/config
/home/n8n/.n8n/config
/var/lib/n8n/credentials

Phase 4: Account Takeover

With extracted credentials, attackers can:

• Access database directly to dump user credentials
• Forge authentication tokens using signing keys
• Impersonate administrative users
• Modify existing workflows to establish persistence
• Exfiltrate sensitive workflow data containing business logic and credentials

Secondary Attack Vectors

Multi-Stage Attacks:

1. Horizontal Privilege Escalation: Access credentials of peer users
2. Vertical Privilege Escalation: Obtain administrative credentials
3. Infrastructure Compromise: Extract cloud provider credentials, database passwords
4. Supply Chain Attacks: Modify workflows to inject malicious code into automated processes

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3. AFFECTED SYSTEMS AND SOFTWARE VERSIONS

Vulnerable Versions

Vendor: n8n-io
Product: n8n Workflow Automation Platform

Affected Version Ranges:

• Branch 1.x: All versions < 1.123.18
• Branch 2.x: All versions < 2.5.0

Deployment Scenarios at Risk

1. Self-Hosted Installations

   • Docker deployments
   • Kubernetes clusters
   • VM-based installations
   • Bare-metal servers

2. Cloud Deployments

   • AWS, Azure, GCP hosted instances
   • Platform-as-a-Service deployments
   • Container orchestration platforms

3. Enterprise Environments

   • Multi-tenant installations (highest risk)
   • Integrated with corporate identity providers
   • Connected to production databases and APIs

Environmental Factors Increasing Risk

• Multi-user environments: Higher likelihood of compromised low-privileged accounts
• Internet-facing instances: Increased attack surface
• Integration with sensitive systems: Greater impact from credential exposure
• Shared hosting: Cross-tenant contamination risk
• Legacy authentication: Environments without MFA or strong authentication

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4. RECOMMENDED MITIGATION STRATEGIES

Immediate Actions (Priority 1 - Within 24-48 Hours)

A. Patch Application

CRITICAL: Apply security updates immediately

# For Docker deployments
docker pull n8nio/n8n:1.123.18  # For 1.x branch
docker pull n8nio/n8n:2.5.0     # For 2.x branch

# Restart containers with updated image
docker-compose down
docker-compose up -d

# For npm installations
npm update n8n@1.123.18  # or @2.5.0

B. Emergency Access Review

1. Audit all user accounts with workflow creation/modification permissions
2. Review workflow history for suspicious file access patterns
3. Check system logs for unusual file read operations
4. Examine authentication logs for anomalous login patterns post-exploitation window

C. Credential Rotation

Assume compromise and rotate all sensitive credentials:

• Database passwords
• API keys and tokens
• JWT signing secrets
• OAuth client secrets
• Service account credentials
• Integration passwords

Short-Term Mitigations (Priority 2 - Within 1 Week)

A. Access Control Hardening

# Implement principle of least privilege
- Restrict workflow creation to trusted users only
- Implement approval workflows for new workflow deployment
- Enable audit logging for all workflow modifications
- Implement role-based access control (RBAC) strictly

B. Network Segmentation

• Place n8n instances behind VPN or zero-trust network access
• Implement IP whitelisting for administrative access
• Segment n8n infrastructure from production databases where possible
• Deploy Web Application Firewall (WAF) with file access monitoring

C. Monitoring and Detection

Deploy detection rules for:

- Workflow creation/modification by low-privileged users
- File read operations outside expected directories
- Multiple failed authentication attempts following workflow changes
- Unusual data exfiltration patterns
- Access to configuration files from workflow context

Long-Term Strategic Mitigations (Priority 3 - Ongoing)

A. Security Architecture Review

1. Implement workflow sandboxing: Containerize workflow execution with minimal file system access
2. Deploy secrets management: Use HashiCorp Vault, AWS Secrets Manager, or Azure Key Vault
3. Implement file access monitoring: Deploy HIDS/FIM solutions
4. Enable comprehensive audit logging: Centralize logs in SIEM

B. Security Hardening

# File system permissions
chmod 600 /app/.env
chown root:root /app/config/*

# Run n8n with minimal privileges
# Use dedicated service account with restricted file access
useradd -r -s /bin/false n8n-service

# Implement AppArmor/SELinux policies
# Restrict file system access for n