Security - https://superuser.com BeaverCheck Audit

F

Subresource Integrity

Action

0 of 1 external resources have SRI

FIX

0 of 1 external resources have SRI

External script from challenges.cloudflare.com lacks integrity attribute

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

Got: https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit

SRI Coverage 0 / 1 of external resources have integrity hashes

Tag	Domain	Integrity
<script>	challenges.cloudflare.com	✗ Missing

D

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=()

D

security.txt

Action

No /.well-known/security.txt published

FIX

security.txt

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

C

Security Headers

Action

5 of 10 headers properly configured

REVIEW

5 of 10 headers properly configured

Strict-Transport-Security is properly configured (consider adding preload)

Got: 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 is properly configured

Got: SAMEORIGIN

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 is present

Got: upgrade-insecure-requests; frame-ancestors 'self' https://stackexchange.com

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: cloudflare

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

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

B

Content Security Policy

3 of 11 CSP checks passed

REVIEW

3 of 11 CSP checks passed

Raw CSP policy

Got: upgrade-insecure-requests; frame-ancestors 'self' https://stackexchange.com

default-src directive is missing

default-src provides a fallback for other directives. Set it to restrict default resource loading.

Expected: default-src 'self'

No script-src or default-src to check for 'unsafe-inline'

No script-src or default-src to check for 'unsafe-eval'

No script-src or default-src to check for wildcard

object-src falls back to default-src

base-uri directive is missing

Without base-uri, attackers can inject a <base> tag to hijack relative URLs. Set it to 'self' or 'none'.

Expected: base-uri 'self'

frame-ancestors directive is set

Got: frame-ancestors 'self' https://stackexchange.com

form-action directive is missing

form-action restricts where forms can submit data, preventing form hijacking.

Expected: form-action 'self'

upgrade-insecure-requests is enabled

Content-Security-Policy-Report-Only is also set

A report-only policy is active alongside the enforcing policy for monitoring.

Got: default-src https: wss: data: blob: 'unsafe-eval' 'unsafe-inline'; frame-ancestors 'self'; report-uri /_/csp-reports

default-src provides a fallback for other directives. Set it to restrict default resource loading.

Expected: default-src 'self'

Why this matters

Security gaps expose your site and users to attacks, eroding trust.

Without base-uri, attackers can inject a <base> tag to hijack relative URLs. Set it to 'self' or 'none'.

Expected: base-uri 'self'

Why this matters

Missing base-uri in CSP leaves a base-tag injection attack path open even on otherwise strict policies.

Learn more ▾

A common omission: developers add CSP for script-src and frame-ancestors but forget base-uri. The result is a CSP that looks strict but lets an attacker rewrite every URL on the page via <base href>. Add `base-uri 'self'` to close the gap.

Source: MDN CSP

form-action restricts where forms can submit data, preventing form hijacking.

Expected: form-action 'self'

Why this matters

Security gaps expose your site and users to attacks, eroding trust.

A report-only policy is active alongside the enforcing policy for monitoring.

Why this matters

Running enforcing + Report-Only in parallel lets you test stricter directives safely before promoting them.

Source: MDN CSP

Parsed Policy

upgrade-insecure-requests

frame-ancestors 'self'https://stackexchange.com

C

Cookie Security

Action

5 cookies analyzed, 11 checks passed

REVIEW

5 cookies analyzed, 11 checks passed

Cookie 'prov' has the Secure flag

Cookie 'prov' has the HttpOnly flag

Cookie 'prov' has SameSite=None

Cookie '__cflb' is missing the Secure flag

Without the Secure flag, this cookie can be sent over unencrypted HTTP, exposing it to interception.

Cookie '__cflb' has the HttpOnly flag

Cookie '__cflb' has SameSite=Lax

Cookie 'prov' is missing the Secure flag

Without the Secure flag, this cookie can be sent over unencrypted HTTP, exposing it to interception.

Cookie 'prov' has the HttpOnly flag

Cookie 'prov' has no SameSite attribute

Without an explicit SameSite attribute, browser default behavior varies. Set SameSite=Lax or Strict.

Cookie '__cf_bm' has the Secure flag

Cookie '__cf_bm' has the HttpOnly flag

Cookie '__cf_bm' has no SameSite attribute

Without an explicit SameSite attribute, browser default behavior varies. Set SameSite=Lax or Strict.

Cookie '_cfuvid' has the Secure flag

Cookie '_cfuvid' has the HttpOnly flag

Cookie '_cfuvid' has SameSite=None

5 cookies analyzed 2 critical 2 warnings

Name	Secure	HttpOnly	SameSite	Size	Issues
prov	✓	✓	None	40 B	2
__cflb	✗	✓	Lax	51 B	1
prov	✗	✓	—	40 B	2
__cf_bm	✓	✓	—	205 B	1
_cfuvid	✓	✓	None	120 B	—

B

CORS Configuration

No CORS headers

REVIEW

No CORS headers

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

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_CHACHA20_POLY1305_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 75 days)

Got: 2026-07-06T16:43:18Z

Certificate chain has 2 certificates

Certificate uses modern signature algorithm

Got: ECDSA-SHA384

Certificate covers 1 domain(s)

Got: superuser.com

Certificate is issued by a trusted CA

Got: CN=E7,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_CHACHA20_POLY1305_SHA256

HTTP Version

HTTP/1.1

Certificate Chain

Leaf Certificate

Subject CN=superuser.comIssuer CN=E7,O=Let's Encrypt,C=USValid 2026-04-07T16:43:19Z → 2026-07-06T16:43:18ZExpires in 75 days SANs superuser.comSignature ECDSA-SHA384Serial 5c4a668b54f5f5b35f2d25799ece6b98b10

Intermediate (CA Certificate)

Subject CN=E7,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 325 days Signature SHA256-RSASerial aa75f1e62b8f0a220966d38bbfd4baa1

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	—

A+

Email Security

DMARC: reject

PASS

DMARC: reject

DMARC policy is reject — strongest protection

DMARC

Policy reject — strongest protection Record v=DMARC1; p=reject; pct=100; rua=mailto:dmarc-aggregates@stackoverflow.com; ruf=mailto:dmarc-forensics@stackoverflow.com; fo=1

A

Transport Security

HTTP/3, HSTS, and TLS version analysis

PASS

HTTP/3, HSTS, and TLS version analysis

HTTP/3 (QUIC) not advertised

HTTP/3 eliminates head-of-line blocking. If your CDN supports it, consider enabling it.

HSTS enabled (includeSubDomains)

TLS 1.3 in use (fastest handshake, 1-RTT)