Defending Against Critical n8n Vulnerabilities: Detection and Remediation

Introduction

Recent research has uncovered two critical vulnerabilities in n8n, a popular open-source workflow automation tool. These flaws, tracked as CVE-2024-44795 and CVE-2024-44796, pose a severe risk to organizations using the platform to integrate AI services and manage business processes.

For defenders, the issue is critical because n8n is often granted high privileges to access databases, APIs, and internal systems. Exploiting these vulnerabilities allows attackers to bypass authentication (CVE-2024-44795) and scan internal networks or steal cloud credentials (CVE-2024-44796). This effectively turns an automation tool into a beachhead for a full-scale supply chain compromise.

Technical Analysis

CVE-2024-44795 (CVSS 9.8 - Critical): Broken Access Control This vulnerability allows unauthenticated attackers to execute arbitrary workflows via specific API endpoints. By bypassing the authentication layer, an attacker can trigger workflows that perform sensitive actions, such as data exfiltration or system modification, without valid credentials.

CVE-2024-44796 (CVSS 9.1 - Critical): Server-Side Request Forgery (SSRF) A flaw in the "HTTP Request" node allows attackers to manipulate outbound requests. This can be leveraged to interact with internal services not exposed to the internet (e.g., metadata services like AWS IMDS or internal admin panels), leading to credential harvesting or lateral movement.

Affected Versions: Versions prior to the fixes released in late September 2024. Administrators must verify they are running the latest patched version to mitigate these risks.

Defensive Monitoring

To detect potential exploitation of these vulnerabilities within your environment, security teams should monitor for suspicious process execution patterns originating from the n8n application (typically running on Node.js) and unexpected network traffic patterns indicative of SSRF.

SIGMA Detection Rules

The following SIGMA rules identify suspicious child processes spawned by n8n (indicative of RCE via workflow execution) and suspicious network connections (indicative of SSRF).

YAML

---
title: Suspicious Child Process Spawned by Node.js (n8n)
id: 8a3b2c1d-4e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects suspicious shell processes spawned by Node.js, potentially indicating exploitation of automation platforms like n8n to achieve RCE.
references:
  - https://www.infosecurity-magazine.com/news/two-critical-flaws-in-n8n-ai/
author: Security Arsenal
date: 2024/09/19
tags:
  - attack.execution
  - attack.t1059.001
  - attack.t1059.003
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: '\node.exe'
    Image|endswith:
      - '\cmd.exe'
      - '\powershell.exe'
      - '\pwsh.exe'
  condition: selection
falsepositives:
  - Legitimate administrative scripts executed by the automation platform
level: high
---
title: n8n SSRF via Node Process Network Connection
id: b4c5d6e7-8f9a-0b1c-2d3e-4f5a6b7c8d9e
status: experimental
description: Detects potential SSRF attempts by identifying Node.js processes connecting to private IP ranges or localhost, common in automation platforms like n8n.
references:
  - https://attack.mitre.org/techniques/T1071/
author: Security Arsenal
date: 2024/09/19
tags:
  - attack.initial_access
  - attack.t1190
  - attack.t1071.001
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Image|endswith: '\node.exe'
    DestinationIp|contains:
      - '127.'
      - '10.'
      - '172.16.'
      - '172.17.'
      - '172.18.'
      - '172.19.'
      - '172.20.'
      - '172.21.'
      - '172.22.'
      - '172.23.'
      - '172.24.'
      - '172.25.'
      - '172.26.'
      - '172.27.'
      - '172.28.'
      - '172.29.'
      - '172.30.'
      - '172.31.'
      - '192.168.'
  condition: selection
falsepositives:
  - Legitimate internal API calls by the automation workflow
level: medium

KQL Queries (Microsoft Sentinel/Defender)

Use these queries to hunt for signs of exploitation or verify the presence of the vulnerable application.

KQL — Microsoft Sentinel / Defender

// Detect Node.js (n8n) spawning shells (Potential RCE)
DeviceProcessEvents
| where InitiatingProcessFileName has "node"
| where FileName in~ ("cmd.exe", "powershell.exe", "pwsh.exe", "bash", "sh")
| project Timestamp, DeviceName, InitiatingProcessCommandLine, FileName, ProcessCommandLine
| order by Timestamp desc

// Detect Node.js connecting to internal IP ranges (Potential SSRF)
DeviceNetworkEvents
| where InitiatingProcessFileName has "node"
| where parse_ipv4(RemoteIP) between(ipv4("10.0.0.0"), ipv4("10.255.255.255")) 
   or parse_ipv4(RemoteIP) between(ipv4("172.16.0.0"), ipv4("172.31.255.255"))
   or parse_ipv4(RemoteIP) between(ipv4("192.168.0.0"), ipv4("192.168.255.255"))
   or RemoteIP startswith "127."
| project Timestamp, DeviceName, InitiatingProcessFileName, RemoteIP, RemotePort, RemoteUrl
| order by Timestamp desc

Velociraptor VQL Artifacts

These VQL hunts can be used to scan endpoints for suspicious process lineage or webshell modifications.

VQL — Velociraptor

-- Hunt for Node.js processes with suspicious children (RCE Indicator)
SELECT Parent.Pid AS ParentPid, Parent.Name AS ParentName, 
       Child.Pid, Child.Name, Child.CommandLine
FROM process_chain( 
    pid=Pid
  )
WHERE Parent.Name =~ "node" 
  AND Child.Name IN ("cmd", "powershell", "pwsh", "bash", "sh")

-- Hunt for file modifications in common n8n directories (Webshell Indicator)
SELECT FullPath, Mtime, Atime, Size, Mode
FROM glob(globs="/*n8n*/**")
WHERE Mtime > now() - 24h
   AND NOT Name =~ "\.log$"

Verification Script

Run this Bash script to check if your n8n instance is vulnerable (assuming npm/node installation).

Bash / Shell

#!/bin/bash
# Check n8n version for CVE-2024-44795 and CVE-2024-44796

echo "Checking n8n version..."

# Check if n8n is installed globally
if command -v n8n &> /dev/null; then
    INSTALLED_VERSION=$(n8n --version)
    echo "Current version: $INSTALLED_VERSION"
    
    # Check against a known safe version (Replace with latest safe version as updates occur)
    # Safe version is generally considered > 1.x.x fix released Sept 2024
    SAFE_VERSION="1.60.0" 
    
    if [ "$(printf '%s
' "$SAFE_VERSION" "$INSTALLED_VERSION" | sort -V | head -n1)" = "$SAFE_VERSION" ]; then
        echo "[INFO] Version $INSTALLED_VERSION appears to be patched (greater than or equal to $SAFE_VERSION)."
    else
        echo "[WARNING] Version $INSTALLED_VERSION is likely vulnerable. Please update immediately."
    fi
else
    echo "n8n command not found in PATH. Checking local packages..."
    npm list -g n8n
fi

Remediation

Patch Immediately: Update n8n to the latest version immediately. Check the official n8n repository or security advisories for the specific patched versions addressing CVE-2024-44795 and CVE-2024-44796.
Network Segmentation: Restrict the outbound network access of the n8n server. Ideally, n8n should only communicate with necessary external APIs and not have unrestricted access to the entire internal network or cloud metadata IPs (169.254.169.254).
Credential Rotation: If you suspect exploitation, immediately rotate all API keys, database credentials, and cloud tokens stored or accessible by n8n. Assume these are compromised.
Audit Workflows: Review existing workflows for unauthorized changes or new workflows that may have been injected by an attacker leveraging the access control bypass.
Hardening: Ensure the n8n instance is not exposed directly to the public internet without strong authentication (e.g., OAuth, SSO) and Web Application Firewall (WAF) protection, although patching remains the primary control.

Related Resources

Security Arsenal Alert Triage Automation AlertMonitor Platform Book a SOC Assessment platform Intel Hub

How to Protect Against Critical n8n Workflow Automation Flaws (CVE-2024-44795 & CVE-2024-44796)