import os from werkzeug.utils import secure_filename
Edward is a Python package used for building and testing web applications. A popular feature of Edward is its support for file uploads. However, a vulnerability was discovered in the file upload feature of Edward, specifically in the FileUpload class. The vulnerability arises from a lack of proper validation and sanitization of user-uploaded files. This allows an attacker to upload malicious files, potentially leading to security breaches. Affected Versions The vulnerability affects Edward versions prior to edwardie==1.2.3 . It is essential to update to the latest version to ensure the security of your application. Proof of Concept A proof of concept (PoC) exploit can be demonstrated using a Python script:
# Sanitize filename filename = secure_filename(file.filename)
import requests
class FileUpload: def save(self, file): # Validate file type if file.filename.split(".")[-1] not in ALLOWED_EXTENSIONS: raise ValueError("Invalid file type")
# Target URL url = "http://example.com/upload"
class FileUpload: def save(self, file): # Insufficient validation and sanitization filename = file.filename file.save(os.path.join(UPLOAD_FOLDER, filename)) The save() method does not check the file type, validate the file contents, or sanitize the filename. To fix the vulnerability, update the FileUpload class to include proper validation and sanitization:
# Malicious file file = open("malicious_file.txt", "rb")
