Grade C — 4 to fix, 5 minor.
passive scan · the deep checks need you signed in · scanned 3h ago
This is a passive website security report for rerun.build, graded C (62/100). We checked its SSL certificate, HTTP security headers, DNS records, email spoofing protection and publicly exposed files — the same surface a browser and a search engine already see.
We found 9 issues on this scan — each has a plain-English explanation and a copy-paste fix below.
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Your site is served over HTTPS but doesn't send a Strict-Transport-Security header. Without it, the first visit (or a link typed as http://) can be intercepted and downgraded to plain HTTP before the redirect happens — a foothold for man-in-the-middle attacks on public Wi-Fi.
There's no Content-Security-Policy header. A CSP is the single most effective defense against cross-site scripting (XSS): it tells the browser which sources of scripts, styles, and other content are allowed, so an injected <script> from a compromised dependency or a reflected input simply won't run.
Nothing stops your site from being embedded in an <iframe> on another domain. An attacker can overlay an invisible frame of your app on their page and trick a logged-in user into clicking buttons they can't see — a clickjacking attack.
Without `X-Content-Type-Options: nosniff`, browsers may guess ("sniff") the type of a response and, for example, run an uploaded file as JavaScript. It's a one-line header that closes a whole class of content-type confusion bugs.
Your responses advertise the exact software you run (X-Powered-By: Next.js). It's not a hole by itself, but it hands attackers a shortcut: they can look up known vulnerabilities for that precise version instead of probing blindly.
The domain rerun.build publishes no SPF record. SPF is the DNS record that lists which mail servers are allowed to send email as your domain. Without it, spam filters have no way to tell your real mail from a forgery, and messages you do send are more likely to land in spam.
The DMARC record on rerun.build uses p=none, which only reports spoofing — it doesn't stop it. Forged mail claiming to be from your domain is still delivered.
rerun.build is not protected by DNSSEC. DNSSEC signs your DNS records so resolvers can detect a forged answer — without it, an attacker who can poison DNS could point your domain at their own server without touching anything you control.
rerun.build publishes no CAA records. CAA tells the world which certificate authorities are allowed to issue HTTPS certificates for your domain. Without it, any CA can be persuaded to issue a cert for your domain, which widens the door to mis-issuance.
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