Security

· 12 checks — HTTP headers, CSP, TLS handshake, and cookie hygiene rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Checks

4 PASS 2 REVIEW 6 FIX

Security Headers

Action

2 of 10 headers properly configured

FIX

2 of 10 headers properly configured

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

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

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

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

Permissions-Policy header is missing

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

Expected: geolocation=(), camera=(), microphone=()

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'

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

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

X-Powered-By header is not present

Server header is present without version info

Got: GitHub.com

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

Content Security Policy

Action

No enforcing CSP policy found

FIX

No enforcing CSP policy found

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

Subresource Integrity

Action

0 of 3 external resources have SRI

FIX

0 of 3 external resources have SRI

External link from fonts.googleapis.com lacks integrity attribute

Without SRI, if this CDN is compromised, attackers could inject malicious code.

Got: //fonts.googleapis.com/css?family=Bitter:400,700

External script from plausible.io lacks integrity attribute

Without SRI, if this CDN is compromised, attackers could inject malicious code.

Got: https://plausible.io/js/plausible.js

External script from ajax.googleapis.com lacks integrity attribute

Without SRI, if this CDN is compromised, attackers could inject malicious code.

Got: //ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js

SRI Coverage 0 / 3 of external resources have integrity hashes

Tag	Domain	Integrity
<link>	fonts.googleapis.com	✗ Missing
<script>	plausible.io	✗ Missing
<script>	ajax.googleapis.com	✗ Missing

Email Security

Action

No DMARC

FIX

No DMARC

No DMARC record found

Without DMARC, email receivers have no policy for handling authentication failures.

DMARC

No DMARC record found

Without DMARC, email receivers have no policy for handling authentication failures from your domain.

Without DMARC, email receivers have no policy for handling authentication failures.

Why this matters

Without DMARC, anyone can send phishing emails using your domain name.

Learn more ▾

DMARC tells receiving mail servers what to do with email that fails SPF/DKIM checks for your domain. With a strict 'p=reject' policy, spoofed emails get bounced; without it they reach the inbox. Domains used in phishing campaigns lose deliverability and brand trust fast.

Source: DMARC.org / NIST

Permissions-Policy

Action

No header set

FIX

No header set

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=()

security.txt

Action

No /.well-known/security.txt published

FIX

security.txt

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

CORS Configuration

Action

Origin: *

REVIEW

Origin: *

Access-Control-Allow-Origin: * — unrestricted

Any website can read this resource's response. Appropriate for public APIs but not for user-specific content.

Origin reflection not testable with a single request

Some servers reflect the request Origin header. This requires manual testing with a crafted Origin header.

CORS Configuration Permissive

Allow-Origin *

Any website can read responses from this resource.

Header	Value	Status
Access-Control-Allow-Origin	*	⚠

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

Known vulnerability matches

Action

6 known vulnerability match(es) against detected tech

REVIEW

Known Vulnerabilities

Library	Version	Severity	Summary	Fixed In
jQuery	1.11.2	medium	3rd party CORS request may execute	1.12.0
jQuery	1.11.2	medium	parseHTML() executes scripts in event handlers	2.2.0
jQuery	1.11.2	low	jQuery 1.x and 2.x are End-of-Life and no longer receiving security updates	2.999.999
jQuery	1.11.2	medium	jQuery before 3.4.0, as used in Drupal, Backdrop CMS, and other products, mishandles jQuery.extend(true, {}, ...) because of Object.prototype pollution	3.4.0
jQuery	1.11.2	medium	passing HTML containing <option> elements from untrusted sources - even after sanitizing it - to one of jQuery's DOM manipulation methods (i.e. .html(), .append(), and others) may execute untrusted code.	3.5.0
jQuery	1.11.2	medium	Regex in its jQuery.htmlPrefilter sometimes may introduce XSS	3.5.0

A+

TLS & Certificates

TLS 1.3, 7 checks passed

PASS

TLS 1.3, 7 checks passed

TLS 1.3 is used

Got: TLS 1.3

Strong cipher suite is used

Got: TLS_AES_128_GCM_SHA256

HTTP/2 is not negotiated

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

Got: http/1.1

Certificate is valid (expires in 46 days)

Got: 2026-05-21T07:36:06Z

Certificate chain has 2 certificates

Certificate uses modern signature algorithm

Got: SHA256-RSA

Certificate covers 2 domain(s)

Got: elixir-lang.org, www.elixir-lang.org

Certificate is issued by a trusted CA

Got: CN=R13,O=Let's Encrypt,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=elixir-lang.orgIssuer CN=R13,O=Let's Encrypt,C=USValid 2026-02-20T07:36:07Z → 2026-05-21T07:36:06ZExpires in 46 days SANs elixir-lang.org, www.elixir-lang.orgSignature SHA256-RSASerial 51ba8928df25c01198b54aae95da07826fb

Intermediate (CA Certificate)

Subject CN=R13,O=Let's Encrypt,C=USIssuer CN=ISRG Root X1,O=Internet Security Research Group,C=USValid 2024-03-13T00:00:00Z → 2027-03-12T23:59:59ZExpires in 342 days Signature SHA256-RSASerial 5a00f212d8d4b480f3924157ea298305

A+

Cookie Security

No cookies set — no cookie security risks

PASS

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

No known JavaScript library vulnerabilities detected

No known JavaScript library vulnerabilities detected.

A+

Information Leakage

No exposures

PASS

No exposures

No security.txt found

Consider adding a security.txt at /.well-known/security.txt.

No sensitive files exposed

No sensitive files exposed — all paths returned 404.

Path	Status	Category	Risk
/.git/HEAD	✓ Not found	Version Control	—
/.git/config	✓ Not found	Version Control	—
/.svn/entries	✓ Not found	Version Control	—
/.env	✓ Not found	Configuration	—
/.env.local	✓ Not found	Configuration	—
/.env.production	✓ Not found	Configuration	—
/wp-config.php	✓ Not found	Configuration	—
/.htaccess	✓ Not found	Configuration	—
/phpinfo.php	✓ Not found	Debug	—
/server-status	✓ Not found	Debug	—
/server-info	✓ Not found	Debug	—
/.well-known/security.txt	✓ Not found	Security Policy	—

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.