Full Report
n8n security advisory (AV26-836)
Analysis Summary
# Vulnerability: Multiple Flaws in n8n (RCE and Arbitrary File Access)
## CVE Details
*Note: Specific CVE IDs were not explicitly listed in the source text, though the advisory references GitHub Security Advisories (GHSA).*
- **CVE ID:** Pending/GHSA-6h4x-896x-fw5m (RCE), GHSA-r4j2-j3wm-q689 (File Read/Write)
- **CVSS Score:** Critical/High (Estimated based on RCE/File Write impact)
- **CWE:** CWE-22 (Path Traversal), CWE-20 (Improper Input Validation)
## Affected Systems
- **Products:** n8n (Workflow Automation Tool)
- **Versions:**
- Versions prior to 1.123.69
- Versions prior to 2.33.4
- Versions prior to 2.34.1
- **Configurations:** Systems utilizing the Model Context Protocol (MCP) Node or the Snowflake Node.
## Vulnerability Description
Two primary vulnerabilities have been identified:
1. **RCE via Path Traversal (MCP Node):** A path traversal flaw exists in the way n8n loads schemas for the Model Context Protocol (MCP) node. This allows an attacker to manipulate file paths, leading to Remote Code Execution (RCE) within the n8n main process.
2. **Arbitrary File Read/Write (Snowflake Node):** The Snowflake node is susceptible to a vulnerability where client-side commands can be leveraged to read from or write to arbitrary files on the host system.
## Exploitation
- **Status:** PoC availability unknown (Assumed disclosed to vendor)
- **Complexity:** Medium
- **Attack Vector:** Network
## Impact
- **Confidentiality:** High (Ability to read sensitive system files and database credentials)
- **Integrity:** High (Ability to write/overwrite system files or execute malicious code)
- **Availability:** High (Potential for system takeover or service disruption)
## Remediation
### Patches
The vendor has released the following patched versions. Users are urged to upgrade immediately:
- **n8n v1.123.69**
- **n8n v2.33.4**
- **n8n v2.34.1**
### Workarounds
- **Disable Vulnerable Nodes:** If immediate patching is not possible, temporarily disable or restrict access to the **MCP Node** and **Snowflake Node** within the n8n environment.
- **Principle of Least Privilege:** Ensure the n8n process is running under a dedicated user with minimal filesystem permissions to limit the impact of file read/write exploits.
## Detection
- **Indicators of Compromise:**
- Unusual file access patterns in system logs.
- Path traversal strings (e.g., `../`, `..\`) appearing in logs related to MCP schema loading.
- Unexpected outbound connections from the n8n main process.
- **Detection methods:** Audit n8n workflow logs for unauthorized use of Snowflake or MCP nodes by non-admin users.
## References
- n8n Security Advisory (GHSA-6h4x-896x-fw5m): hxxps[://]github[.]com/n8n-io/n8n/security/advisories/GHSA-6h4x-896x-fw5m
- n8n Security Advisory (GHSA-r4j2-j3wm-q689): hxxps[://]github[.]com/n8n-io/n8n/security/advisories/GHSA-r4j2-j3wm-q689
- n8n Security Center: hxxps[://]github[.]com/n8n-io/n8n/security
- Canadian Centre for Cyber Security Advisory: hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/n8n-security-advisory-av26-836