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Security

· 12 checks — HTTP headers, CSP, TLS handshake, and cookie hygiene rolled into one auditable list.
SCORE
73
GRADE
C
FIX
3
REVIEW
4
PASS
5
INFO
0
Checks
12
5 PASS 4 REVIEW 3 FIX
F
Subresource Integrity
Action
0 of 1 external resources have SRI
FIX
0 of 1 external resources have SRI
Warning::
External script from piwik.proxmox.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://piwik.proxmox.com/matomo.js
SRI Coverage 0 / 1 of external resources have integrity hashes
TagDomainIntegrity
<script>piwik.proxmox.com Missing
F
Email Security
Action
No DMARC
FIX
No DMARC
Warning::
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

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=()
B
Security Headers
7 of 10 headers properly configured
REVIEW
7 of 10 headers properly configured
Warning::
HSTS is missing includeSubDomains
Without includeSubDomains, subdomains can still be accessed over HTTP.
Got: max-age=31536000 Expected: max-age=31536000; includeSubDomains
Info::
X-Content-Type-Options is properly configured
Got: nosniff
Info::
X-Frame-Options is properly configured
Got: SAMEORIGIN
Info::
Referrer-Policy is properly configured
Got: 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=()
Info::
Content-Security-Policy is present
Got: frame-ancestors 'self'
Info::
Cross-Origin-Opener-Policy is properly configured
Got: 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 not present

Without includeSubDomains, subdomains can still be accessed over HTTP.

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

Without includeSubDomains, a forgotten dev subdomain over HTTP can set malicious cookies that ride to the apex.

Learn more

HSTS without includeSubDomains protects only the exact domain. Cookies set on a non-HSTS subdomain can ride to the apex via cookie-scope attacks. The fix is one directive append. Verify all subdomains support HTTPS first — adding includeSubDomains to a domain with HTTP-only subdomains breaks them.

Source: RFC 6797

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

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
2 of 10 CSP checks passed
REVIEW
2 of 10 CSP checks passed
Info::
Raw CSP policy
Got: frame-ancestors 'self'
Warning::
default-src directive is missing
default-src provides a fallback for other directives. Set it to restrict default resource loading.
Expected: default-src 'self'
Info::
No script-src or default-src to check for 'unsafe-inline'
Info::
No script-src or default-src to check for 'unsafe-eval'
Info::
No script-src or default-src to check for wildcard
Info::
object-src falls back to default-src
Warning::
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'
Info::
frame-ancestors directive is set
Got: frame-ancestors 'self'
Warning::
form-action directive is missing
form-action restricts where forms can submit data, preventing form hijacking.
Expected: form-action 'self'
Info::
upgrade-insecure-requests is not set
This directive upgrades HTTP resources to HTTPS automatically, preventing mixed content.
Expected: upgrade-insecure-requests

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.

This directive upgrades HTTP resources to HTTPS automatically, preventing mixed content.

Expected: upgrade-insecure-requests
Why this matters

Without upgrade-insecure-requests, any HTTP subresource link survives as a mixed-content warning instead of auto-upgrading.

Learn more

Adding `upgrade-insecure-requests` to your CSP turns every http:// subresource fetch into https:// at the browser layer. One-line defense against accidental mixed content from legacy links or third-party widgets.

Source: MDN CSP

Parsed Policy

frame-ancestors 'self'
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
security.txt
Published with 1 contact(s)
REVIEW

security.txt

Contact: mailto:security@proxmox.com
Expires: 2032-08-28T22:00:00.000Z
Encryption: https://enterprise.proxmox.com/debian/security-report.gpg.pub
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_CHACHA20_POLY1305_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 21 days)
Got: 2026-05-13T23:18:23Z
Warning::
Certificate expires soon (21 days remaining)
Renew the certificate before it expires to avoid browser warnings.
Got: 2026-05-13T23:18:23Z
Info::
Certificate chain has 2 certificates
Info::
Certificate uses modern signature algorithm
Got: ECDSA-SHA384
Info::
Certificate covers 7 domain(s)
Got: maurer-it.com, newsletter.proxmox.com, proxmox.com, proxmox.it, www.maurer-it.com, www.proxmox.com, www.proxmox.it
Info::
Certificate is issued by a trusted CA
Got: CN=E8,O=Let's Encrypt,C=US

Renew the certificate before it expires to avoid browser warnings.

Why this matters

Cert expiry within the renewal window — fix now while there's no user impact, instead of after expiry when there's a full outage.

Learn more

Most CAs recommend renewal at 30 days remaining. Inside that window, schedule the renewal immediately and verify auto-renewal is configured if applicable. Don't wait until 7 days; weekend / holiday timing can leave you exposed.

Source: Let's Encrypt / CA renewal best practice

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=proxmox.comIssuer CN=E8,O=Let's Encrypt,C=USValid 2026-02-12T23:18:24Z → 2026-05-13T23:18:23ZExpires in 21 days — expiring soon! SANs maurer-it.com, newsletter.proxmox.com, proxmox.com, proxmox.it, www.maurer-it.com, www.proxmox.com, www.proxmox.itSignature ECDSA-SHA384Serial 60139331ba3bb94667a580ee9f0dd33600b
Intermediate (CA Certificate)
Subject CN=E8,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 324 days Signature SHA256-RSASerial 63959363c24e7082715918bfc3d7ed56
A+
Cookie Security
1 cookies analyzed, 2 checks passed
PASS
1 cookies analyzed, 2 checks passed
Info::
Cookie '2f4d6fdc46bcd694b9e7af987293628a' has the Secure flag
Info::
Cookie '2f4d6fdc46bcd694b9e7af987293628a' has the HttpOnly flag
Warning::
Cookie '2f4d6fdc46bcd694b9e7af987293628a' has no SameSite attribute
Without an explicit SameSite attribute, browser default behavior varies. Set SameSite=Lax or Strict.
1 cookies analyzed 1 warnings
NameSecureHttpOnlySameSiteSizeIssues
2f4d6fdc46bcd694b9e7af987293628a64 B1
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::
security.txt is present — good practice
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 ExposedSecurity PolicyInfo
A
Transport Security
HTTP/3, HSTS, and TLS version analysis
PASS
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.
Info::
HSTS enabled (base policy)
Info::
HSTS missing includeSubDomains
Without includeSubDomains, HSTS only protects the exact domain.
Info::
TLS 1.3 in use (fastest handshake, 1-RTT)
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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