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Security

· 12 checks — HTTP headers, CSP, TLS handshake, and cookie hygiene rolled into one auditable list.
SCORE
60
GRADE
D
FIX
6
REVIEW
2
PASS
4
INFO
0
Checks
12
4 PASS 2 REVIEW 6 FIX
F
Security Headers
Action
2 of 10 headers properly configured
FIX
2 of 10 headers properly configured
Critical::
HSTS header is missing
Strict-Transport-Security forces browsers to use HTTPS, preventing downgrade attacks. Add the header with a max-age of at least 1 year.
Expected: max-age=31536000; includeSubDomains
Warning::
X-Content-Type-Options header is missing
This header prevents MIME-type sniffing, which can lead to XSS attacks. Set it to 'nosniff'.
Expected: nosniff
Warning::
X-Frame-Options header is missing
This header prevents clickjacking by controlling who can embed your page in a frame. Set it to DENY or SAMEORIGIN.
Expected: DENY
Warning::
Referrer-Policy header is missing
Controls how much referrer information is sent with requests. Set to 'strict-origin-when-cross-origin' or stricter.
Expected: strict-origin-when-cross-origin
Warning::
Permissions-Policy header is missing
Controls which browser features (camera, microphone, geolocation) are allowed. Set it to restrict unused features.
Expected: geolocation=(), camera=(), microphone=()
Critical::
Content-Security-Policy header is missing
CSP is the most important header for preventing XSS attacks. See the CSP section for detailed analysis.
Expected: default-src 'self'
Warning::
Cross-Origin-Opener-Policy header is missing
COOP isolates your browsing context, preventing cross-origin side-channel attacks. Set to 'same-origin'.
Expected: same-origin
Warning::
Cross-Origin-Embedder-Policy header is missing
COEP prevents loading cross-origin resources without explicit permission. Required for SharedArrayBuffer and high-resolution timers.
Expected: require-corp
Info::
X-Powered-By header is not present
Info::
Server header is present without version info
Got: AmazonS3

Strict-Transport-Security forces browsers to use HTTPS, preventing downgrade attacks. Add the header with a max-age of at least 1 year.

Expected: max-age=31536000; includeSubDomains
Why this matters

Without HSTS, a network attacker can downgrade the very first connection to HTTP and steal the user's session.

Learn more

HSTS tells browsers 'never speak HTTP to this domain again.' Without it, a network attacker (public WiFi, malicious ISP, hostile DNS) intercepts the first HTTP attempt and serves a downgraded version of your site. One header, big surface reduction.

Source: RFC 6797 / OWASP

CSP is the most important header for preventing XSS attacks. See the CSP section for detailed analysis.

Expected: default-src 'self'
Why this matters

Without a CSP, a single XSS bug can exfiltrate everything your users type — including credentials.

Learn more

Content-Security-Policy is the browser-enforced firewall against XSS. With a strict CSP, a script injection that would otherwise steal session cookies or rewrite the page is silently blocked. Without it, your only defense is hoping every input on every form is escaped correctly forever.

Source: OWASP / MDN

This header prevents MIME-type sniffing, which can lead to XSS attacks. Set it to 'nosniff'.

Expected: nosniff
Why this matters

MIME sniffing lets browsers run uploaded files as JavaScript, turning a file upload into an XSS.

Learn more

Setting X-Content-Type-Options: nosniff tells browsers to trust your declared Content-Type instead of guessing. Without it, an attacker who uploads a polyglot file can sometimes get it executed as a script. One header, no downside.

Source: OWASP / MDN

This header prevents clickjacking by controlling who can embed your page in a frame. Set it to DENY or SAMEORIGIN.

Expected: DENY
Why this matters

Without frame protection, your site can be embedded in a hostile page and used for clickjacking.

Learn more

Clickjacking overlays your site under a transparent malicious page so users click invisible buttons. Setting X-Frame-Options: DENY (or a modern frame-ancestors CSP directive) blocks the embedding entirely. There's almost never a legitimate reason to allow it.

Source: OWASP / MDN

Controls how much referrer information is sent with requests. Set to 'strict-origin-when-cross-origin' or stricter.

Expected: strict-origin-when-cross-origin
Why this matters

Default browser behavior leaks full URLs (including query params and tokens) to every third-party resource — set a strict policy.

Learn more

Without a Referrer-Policy header, browsers send the full referring URL with images, scripts, and fonts loaded from third-party origins. URLs containing tokens, user IDs, or session params end up in third-party logs. Set `Referrer-Policy: strict-origin-when-cross-origin` (or stricter) to limit leakage.

Source: MDN / W3C

Controls which browser features (camera, microphone, geolocation) are allowed. Set it to restrict unused features.

Expected: geolocation=(), camera=(), microphone=()
Why this matters

Permissions-Policy locks down browser APIs you don't use — without it, every page can request camera/mic/geolocation if XSS lands.

Learn more

By default every page can request the camera, microphone, geolocation, payment APIs, and dozens more. Permissions-Policy turns off the ones you don't need so a future bug can't quietly start using them. It's a defense-in-depth header — one line, big surface reduction.

Source: MDN / W3C

COOP isolates your browsing context, preventing cross-origin side-channel attacks. Set to 'same-origin'.

Expected: same-origin
Why this matters

COOP isolates your top-level browsing context from cross-origin windows — without it, popup-based side-channel attacks remain possible.

Learn more

Cross-Origin-Opener-Policy: same-origin prevents cross-origin pages from sharing a browsing-context group with yours. This blocks cross-window references that enable Spectre-style timing attacks and tab-nabbing. Required if you want to enable SharedArrayBuffer.

Source: MDN / web.dev

COEP prevents loading cross-origin resources without explicit permission. Required for SharedArrayBuffer and high-resolution timers.

Expected: require-corp
Why this matters

COEP enforces that all embedded resources opt-in to cross-origin embedding — required for cross-origin isolation features.

Learn more

Cross-Origin-Embedder-Policy: require-corp ensures every embedded resource (script, iframe, image) explicitly allows being loaded cross-origin. Combined with COOP, this enables the cross-origin-isolated context that unlocks SharedArrayBuffer, high-resolution timers, and other powerful APIs.

Source: MDN / web.dev

F
Content Security Policy
Action
No enforcing CSP policy found
FIX
No enforcing CSP policy found
Critical::
No Content-Security-Policy header found
CSP is the most effective defense against XSS attacks. Add a Content-Security-Policy header to restrict resource loading.
Expected: default-src 'self'

CSP is the most effective defense against XSS attacks. Add a Content-Security-Policy header to restrict resource loading.

Expected: default-src 'self'
Why this matters

Without a CSP, a single XSS bug can exfiltrate everything users type — credentials, payment data, session tokens.

Learn more

Content-Security-Policy is the browser-enforced firewall against XSS. With a strict CSP, a script injection that would otherwise steal session cookies is silently blocked. Without it, your only defense is hoping every input on every form is escaped correctly forever. Start in Report-Only mode, fix violations, then graduate to enforcing.

Source: OWASP / MDN

F
Subresource Integrity
Action
0 of 35 external resources have SRI
FIX
0 of 35 external resources have SRI
Warning::
External script from www.googletagmanager.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://www.googletagmanager.com/gtag/js?id=G-CHJJ1RJL5K&cx=c&_slc=1
Warning::
External script from www.google-analytics.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://www.google-analytics.com/plugins/ua/linkid.js
Warning::
External script from app.posthog.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://app.posthog.com/static/array.js
Warning::
External script from www.google-analytics.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: //www.google-analytics.com/analytics.js
Warning::
External link from fonts.googleapis.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,200..900;1,8..60,200..900&display=swap
Warning::
External link from fonts.googleapis.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,100..1000;1,9..40,100..1000&display=swap
Warning::
External script from maps.googleapis.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://maps.googleapis.com/maps/api/js?key=AIzaSyC0BuJ43Ncbmuro17vVxWJWrOzzAPZ0rQE&libraries=places&language=en
Warning::
External script from cdn.dfsdk.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://cdn.dfsdk.com/js/v6/agent.umd.js
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/ycdc-new-C8aNg4J7.css
Warning::
External script from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/ycdc-new-DuyEV27T.js
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/ApplyBanner-CRsOsJga.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/NewNavbarItem-Jh9CXKjI.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/NewPage-7v7qrga6.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/WhyPage-DFDzpL99.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/styles-CgzI4m3t.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/SharedDirectory-BCp7r9c8.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/nouislider-v_DV34yi.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/YCAlerts-CP8TjBWF.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/Dropdown-Bj_lTKYz.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/Breadcrumb-MStH19Bt.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/PartnersPage-ChhbFxOI.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/ApplyToYCPage-y3ZQ-TZC.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/LaunchesPage-on-pn-qp.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/react-datepicker-BWcuNA17.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/dist-DZ0w4YR5.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/editor-DGH5PXuQ.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/Launches-FP6lVcd-.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/LaunchesFormPage-BgKTj1iv.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/LaunchesIndexPage-BaiEH-wM.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/LaunchesShowPage-DoYn1TVx.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/YouTube-pzuUIErF.css
Warning::
External link from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/vite/assets/components-CG_FStur.css
Warning::
External script from bookface-static.ycombinator.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://bookface-static.ycombinator.com/assets/blog-54db898b518e809d1aaeaacf7e7cc20fa35375fb3348fc2b56cea781f5cdfa55.js
Warning::
External script from us-assets.i.posthog.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://us-assets.i.posthog.com/static/surveys.js?v=1.369.5
Warning::
External script from us-assets.i.posthog.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://us-assets.i.posthog.com/array/phc_kqzJJG8aN5nevL0k1oW4Z8iAGswsxBnsWqIBcOuxjah/config.js
SRI Coverage 0 / 35 of external resources have integrity hashes
TagDomainIntegrity
<script>www.googletagmanager.com Missing
<script>www.google-analytics.com Missing
<script>app.posthog.com Missing
<script>www.google-analytics.com Missing
<link>fonts.googleapis.com Missing
<link>fonts.googleapis.com Missing
<script>maps.googleapis.com Missing
<script>cdn.dfsdk.com Missing
<link>bookface-static.ycombinator.com Missing
<script>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<link>bookface-static.ycombinator.com Missing
<script>bookface-static.ycombinator.com Missing
<script>us-assets.i.posthog.com Missing
<script>us-assets.i.posthog.com Missing
D
Email Security
Action
DMARC: none
FIX
DMARC: none
Warning::
DMARC policy is none — monitoring only
This only monitors, it doesn't block spoofed emails. Change to p=quarantine or p=reject.
DMARC
Policy none — monitoring only, does not block spoofing Record v=DMARC1; p=none; pct=100; sp=none; ruf=mailto:dmarc-reports+f@ycombinator.com; rua=mailto:dmarc-reports@ycombinator.com; aspf=r;

This only monitors, it doesn't block spoofed emails. Change to p=quarantine or p=reject.

Why this matters

DMARC p=none collects reports but doesn't actually block spoofed mail — phishing emails still reach inboxes.

Learn more

DMARC's three policies are p=none (monitor only), p=quarantine (mark as spam), and p=reject (bounce). Most domains start at p=none to gather data, but stay there forever, leaving spoofers unblocked. After 30 days of clean DMARC reports, graduate to p=quarantine, then p=reject.

Source: DMARC.org / NIST

D
Permissions-Policy
Action
No header set
FIX
No header set
Warning::
No Permissions-Policy header
Consider adding a Permissions-Policy header to restrict browser feature access from embedded content.

No Permissions-Policy header set.

Without this header, embedded iframes can request access to sensitive device features.

Suggested header
Permissions-Policy: camera=(), microphone=(), geolocation=(), payment=(), usb=()
D
security.txt
Action
No /.well-known/security.txt published
FIX

security.txt

No security.txt found at /.well-known/security.txt

B
CORS Configuration
No CORS headers
REVIEW
No CORS headers
Info::
No CORS headers present — secure default
CORS Configuration Secure

No CORS headers detected.

Cross-origin requests are blocked by browser same-origin policy.

Origin reflection test

Some servers mirror the request Origin header, which can be exploited. Test manually:

curl -sI -H "Origin: https://evil.com" <url> | grep -i access-control
B
Transport Security
HTTP/3, HSTS, and TLS version analysis
REVIEW
HTTP/3, HSTS, and TLS version analysis
Info::
HTTP/3 (QUIC) not advertised
HTTP/3 eliminates head-of-line blocking. If your CDN supports it, consider enabling it.
Warning::
Missing Strict-Transport-Security header
HSTS tells browsers to only use HTTPS, preventing SSL stripping attacks.
Info::
TLS 1.3 in use (fastest handshake, 1-RTT)
A+
TLS & Certificates
TLS 1.3, 7 checks passed
PASS
TLS 1.3, 7 checks passed
Info::
TLS 1.3 is used
Got: TLS 1.3
Info::
Strong cipher suite is used
Got: TLS_AES_128_GCM_SHA256
Info::
HTTP/2 is not negotiated
HTTP/2 provides multiplexing and header compression for better performance.
Got: http/1.1
Info::
Certificate is valid (expires in 262 days)
Got: 2027-01-08T23:59:59Z
Info::
Certificate chain has 3 certificates
Info::
Certificate uses modern signature algorithm
Got: SHA256-RSA
Info::
Certificate covers 2 domain(s)
Got: ycombinator.com, *.ycombinator.com
Info::
Certificate is issued by a trusted CA
Got: CN=Amazon RSA 2048 M04,O=Amazon,C=US

HTTP/2 provides multiplexing and header compression for better performance.

Why this matters

HTTP/1.1 forces the browser to make sequential requests, multiplying latency on every page.

Learn more

HTTP/2 (and HTTP/3) multiplex many requests over a single connection, eliminating head-of-line blocking. HTTP/1.1 forces the browser to either queue requests or open many parallel connections — both worse. Most modern web servers support HTTP/2 with one config line.

Source: MDN Web Docs

Connection
Protocol
TLS 1.3
Cipher Suite
TLS_AES_128_GCM_SHA256
HTTP Version
HTTP/1.1

Certificate Chain

Leaf Certificate
Subject CN=ycombinator.comIssuer CN=Amazon RSA 2048 M04,O=Amazon,C=USValid 2025-12-11T00:00:00Z → 2027-01-08T23:59:59ZExpires in 262 days SANs ycombinator.com, *.ycombinator.comSignature SHA256-RSASerial 43b2fd21f2606d29ac820312bc9fdc4
Intermediate (CA Certificate)
Subject CN=Amazon RSA 2048 M04,O=Amazon,C=USIssuer CN=Amazon Root CA 1,O=Amazon,C=USValid 2022-08-23T22:26:35Z → 2030-08-23T22:26:35ZExpires in 1585 days Signature SHA256-RSASerial 773124f2a952e3ed18a58bdb85d1bc0ce5f27
Intermediate (CA Certificate)
Subject CN=Amazon Root CA 1,O=Amazon,C=USIssuer CN=Starfield Services Root Certificate Authority - G2,O=Starfield Technologies\, Inc.,L=Scottsdale,ST=Arizona,C=USValid 2015-05-25T12:00:00Z → 2037-12-31T01:00:00ZExpires in 4271 days Signature SHA256-RSASerial 67f944a2a27cdf3fac2ae2b01f908eeb9c4c6
A+
Cookie Security
No cookies set — no cookie security risks
PASS
No cookies set — no cookie security risks
Info::
No cookies set — no cookie security risks

No cookies detected — no cookie security risks to report.

A+
JS Library Vulnerabilities
No known vulnerabilities
PASS
No known vulnerabilities
Info::
No known JavaScript library vulnerabilities detected

No known JavaScript library vulnerabilities detected.

A+
Information Leakage
No exposures
PASS
No exposures
Info::
No security.txt found
Consider adding a security.txt at /.well-known/security.txt.
Info::
No sensitive files exposed

No sensitive files exposed — all paths returned 404.

PathStatusCategoryRisk
/.git/HEAD Not foundVersion Control
/.git/config Not foundVersion Control
/.svn/entries Not foundVersion Control
/.env Not foundConfiguration
/.env.local Not foundConfiguration
/.env.production Not foundConfiguration
/wp-config.php Not foundConfiguration
/.htaccess Not foundConfiguration
/phpinfo.php Not foundDebug
/server-status Not foundDebug
/server-info Not foundDebug
/.well-known/security.txt Not foundSecurity Policy
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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