Use of unsanitized data to open file

문서 > Datadog 보안 > Code Security > Static Code Analysis (SAST) > SAST 규칙 > Use of unsanitized data to open file

이 페이지는 아직 영어로 제공되지 않습니다. 번역 작업 중입니다.
현재 번역 프로젝트에 대한 질문이나 피드백이 있으신 경우 언제든지 연락주시기 바랍니다.

Metadata

ID: python-flask/open-file-unsanitized-data

Language: Python

Severity: Error

Category: Security

CWE: 22

Description

Use of unsanitized from incoming request, leading to potential data leak and lack of control of the service. Do not use unsanitized data to control file operations. The code should check any incoming data and make sure it’s safe to use it.

Learn More

CWE-22: CWE-22: Improper Limitation of a Pathname to a Restricted Directory

Non-Compliant Code Examples

@app.route("/read")
def read_file():
    filename = request.args.get("filename")
    if not filename:
        return "Missing 'filename' parameter", 400
    try:
        with open(filename, "r") as f:
            content = f.read()
            return f"<pre>{content}</pre>"
    except Exception as e:
        return f"Error: {str(e)}", 500

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=80)

import flask
import requests

app = flask.Flask(__name__)


@app.route("/route/to/resource/<resource_id>")
def resource1(resource_id):
    with open(resource_id) as f:
        pass
    with open(f"/path/to/{resource_id}") as f:
        pass
    with open("/path/to/{0}".format(resource_id)) as f:
        pass
    with open("/path/to/{0}".other(resource_id)) as f:
        pass

@app.route("/route/to/resource/<resource_id>")
def resource2(resource_id):
    file1 = open(resource_id)
    file2 = open(f"/path/to/{resource_id}")
    file3 = open("/path/to/{0}".format(resource_id))


@app.route("/route/to/resource")
def resource2():
    resource_id = flask.request.args.get("resource_id")
    file1 = open(resource_id)
    file2 = open(f"/path/to/{resource_id}")
    file3 = open("/path/to/{0}".format(resource_id))

from flask import Flask, request, render_template


app = Flask(__name__, static_url_path='/static', static_folder='static')
app.config['DEBUG'] = True


@app.route("/")
def start():
    return render_template("index.html")

Compliant Code Examples

import flask
import requests

app = flask.Flask(__name__)

@app.route("/route/to/resource/<resource_id>")
def resource2(resource_id):
    sanitized_resource_id = sanitize(resource_id)
    file1 = open(sanitized_resource_id)