21cn.pl

.pl crawl

First seen 2026-05-28 · Last seen 2026-05-28 · ok HTTP/1.1 200 287 ms crawled 2026-05-30

PL · 85.128.209.99 · AS15967 Nazwa.pl Sp.z.o.o.

Reputation 87/100 weak security headers no dmarc policy

Classifying

HTML metadata

Title: 21CN - Software & Testing House
Description: Better quality of software. We co-create the quality of software development and adapt to your work style and requirements.
Language: en

Open Graph

url: http://21cn.pl/
title: 21CN - Software & Testing House
description: Better quality of software. We co-create the quality of software development and adapt to your work style and requirements.

Technology

Server: Apache
jQuery: 3.5.1

Analytics

Google Tag Manager

Third-party hosts loaded (6)

cdn.jsdelivr.net×2
ajax.googleapis.com×1
kit.fontawesome.com×1
static1.clutch.co×1
www.google.com×1
www.googletagmanager.com×1

Social

Contact

Email

Phone

DNS records live

NS

ns1.nazwa.pl
ns2.nazwa.pl
ns3.nazwa.pl

MX

10 21cn.pl

Email authentication weak

SPF: v=spf1 mx a include:_spf.google.com -all
strict (-all)
DMARC: not published
DKIM: no key found at common selectors

Certificate (current)

nazwaSSL DV TLS G2 E29 CA

from 2026-04-08 to 2026-10-07

Expires in 128 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 30/100 Checked live page: https://21cn.pl/

findings

missing HSTS
missing Content Security Policy
missing frame protection
missing content type protection
missing Referrer Policy
missing Permissions Policy

Links to (11)

Linked from (1)

testerzy.pl×1