CVE-2023-41319

Fides open-source platform allows arbitrary code execution via webserver API in versions 2.11.0 to 2.19.0 with CONNECTOR_TEMPLATE_REGISTER authorization scope and enabled allow_custom_connector_functions

• CVSS 7.2
• CWE-94 Improper Control of Generation of Code ('Code Injection')
• Authentication, Authorization, and Session Management
• Local

Fides is an open-source privacy engineering platform for managing the fulfillment of data privacy requests in a runtime environment, and the enforcement of privacy regulations in code. The Fides webserver API allows custom integrations to be uploaded as a ZIP file. This ZIP file must contain YAML files, but Fides can be configured to also accept the inclusion of custom Python code in it. The custom code is executed in a restricted, sandboxed environment, but the sandbox can be bypassed to execute any arbitrary code. The vulnerability allows the execution of arbitrary code on the target system within the context of the webserver python process owner on the webserver container, which by default is `root`, and leverage that access to attack underlying infrastructure and integrated systems. This vulnerability affects Fides versions `2.11.0` through `2.19.0`. Exploitation is limited to API clients with the `CONNECTOR_TEMPLATE_REGISTER` authorization scope. In the Fides Admin UI this scope is restricted to highly privileged users, specifically root users and users with the owner role. Exploitation is only possible if the security configuration parameter `allow_custom_connector_functions` is enabled by the user deploying the Fides webserver container, either in `fides.toml` or by setting the env var `FIDES__SECURITY__ALLOW_CUSTOM_CONNECTOR_FUNCTIONS=True`. By default this configuration parameter is disabled. The vulnerability has been patched in Fides version `2.19.0`. Users are advised to upgrade to this version or later to secure their systems against this threat. Users unable to upgrade should ensure that `allow_custom_connector_functions` in `fides.toml` and the `FIDES__SECURITY__ALLOW_CUSTOM_CONNECTOR_FUNCTIONS` are both either unset or explicit set to `False`.

CVE

CVE-2023-41319

CWE

CWE-94 Improper Control of Generation of Code ('Code Injection')

CVSS base score

7.2

Published

2023-09-06

OWASP

A05 Security Misconfiguration

Orthogonal defect classification

Function

Code defect classification

Incorrect Functionality

Category

Authentication, Authorization, and Session Management

Subcategory

Privilege Escalation

Accessibility scope

Local

Impact

Arbitrary Code Execution

Fixed by upgrading

Yes

Solution

Upgrade to Fides version 2.19.0 or later.

import os
import zipfile
import importlib.util

def process_uploaded_zip(zip_file_path):
    with zipfile.ZipFile(zip_file_path, 'r') as zip_file:
        zip_file.extractall('/tmp/custom_connectors')

    for file_name in os.listdir('/tmp/custom_connectors'):
        if file_name.endswith('.py'):
            file_path = os.path.join('/tmp/custom_connectors', file_name)
            spec = importlib.util.spec_from_file_location("custom_connector", file_path)
            custom_connector = importlib.util.module_from_spec(spec)
            spec.loader.exec_module(custom_connector)

def upload_connector(zip_file):
    process_uploaded_zip(zip_file)

import os
import zipfile
import importlib.util
import re

ALLOWED_EXTENSIONS = {'.py'}

def check_filename(filename):
    return not re.search(r'(\.\.|\/)', filename)

def process_uploaded_zip(zip_file_path):
    extraction_dir = '/tmp/custom_connectors'
    os.makedirs(extraction_dir, exist_ok=True)

    with zipfile.ZipFile(zip_file_path, 'r') as zip_file:
        for file_name in zip_file.namelist():
            if not check_filename(file_name):
                raise ValueError(f"Unsafe file path detected: {file_name}")
            if any(not file_name.endswith(ext) for ext in ALLOWED_EXTENSIONS):
                continue
            zip_file.extract(file_name, extraction_dir)

    for file_name in os.listdir(extraction_dir):
        if file_name.endswith('.py'):
            file_path = os.path.join(extraction_dir, file_name)
            spec = importlib.util.spec_from_file_location("custom_connector", file_path)
            custom_connector = importlib.util.module_from_spec(spec)
            spec.loader.exec_module(custom_connector)

def upload_connector(zip_file):
    process_uploaded_zip(zip_file)

@misc{vaitp:cve202341319,
  title        = {{Fides open-source platform allows arbitrary code execution via webserver API in versions 2.11.0 to 2.19.0 with CONNECTOR_TEMPLATE_REGISTER authorization scope and enabled allow_custom_connector_functions}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-41319},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-41319/}}
}