indexo.dev

systemerrorbook.com

.com crawl

First seen 2026-04-13 · Last seen 2026-05-04 · ok HTTP/1.1 200 401 ms crawled 2026-05-07

US · 160.153.0.201 · AS209242 Cloudflare London, LLC

Reputation 95/100 weak security headers

Classifying

HTML metadata

Title
System Error Book – System Error Book
Language
en-US
Generator
Elementor 4.0.7; features: additional_custom_breakpoints; settings: css_print_method-external, google_font-enabled, font_display-auto
Canonical
https://systemerrorbook.com/
Feeds

Technology

CDN
Cloudflare
CMS
WordPress

Third-party hosts loaded (2)

  • gmpg.org×1
  • systemerror.substack.com×1

Contact

Phone
Address
rd as a computer science professor in 2007

Registration

Registrar
GoDaddy.com, LLC
Created
2021-01-24
Expires
2027-01-24 250 days left
Updated
2026-01-25
Name servers
  • ns15.domaincontrol.com
  • ns16.domaincontrol.com

DNS records live

NS
  • ns15.domaincontrol.com
  • ns16.domaincontrol.com
TXT
  • ca3-ab4142ae5af04c5da8b6b10d6f570f08

Email authentication no MX

SPF
not published
DMARC
not published
DKIM
no key found at common selectors

Certificate (current)

WE1
from 2026-04-26 to 2026-07-25
Expires in 67 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 35/100 Checked live page: https://systemerrorbook.com/

present
  • permissions-policy
findings
  • missing HSTS
  • missing Content Security Policy
  • missing frame protection
  • missing content type protection
  • missing Referrer Policy
Header values
permissions-policy
private-state-token-redemption=(self "https://www.google.com" "https://www.gstatic.com" "https://recaptcha.net" "https://challenges.cloudflare.com" "https://hcaptcha.com"), private-state-token-issuance=(self "https://www.google.com" "https://www.gstatic.com" "https://recaptcha.net" "https://challenges.cloudflare.com" "https://hcaptcha.com")

Links to (17)

Linked from (1)