WebForensik

HSTS (HTTP Strict Transport Security) tells the browser: "Always use HTTPS for this domain — no matter what." This prevents attackers on the same WLAN from intercepting the first, unprotected request. Prerequisite: your site is already stable on HTTPS.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
</IfModule>

⚠ max-age=31536000 equals 1 year (in seconds). includeSubDomains also covers blog.your-domain.com, shop.your-domain.com etc. — only enable if ALL subdomains support HTTPS, otherwise they become unreachable.

# BEGIN WebForensik HSTS
<IfModule mod_headers.c>
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
</IfModule>
# END WebForensik HSTS

add_action('send_headers', function () {
    header('Strict-Transport-Security: max-age=31536000; includeSubDomains');
});

✓ How to verify it works: DevTools (F12) → Network tab → reload page → click the first request → "Response Headers" — must contain "strict-transport-security: max-age=31536000…".

A Content Security Policy (CSP) is a doorkeeper rule for the browser: "Scripts and styles may only be loaded from these allowed sources." Without CSP, injected malicious code (XSS) can freely fetch anything. Start with a simple, secure baseline.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set Content-Security-Policy "default-src 'self'; img-src 'self' data: https:; style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline'; font-src 'self' https: data:; object-src 'none'; frame-ancestors 'self'; base-uri 'self'"
</IfModule>

⚠ This policy is intentionally pragmatic (allows inline styles since many themes/plugins rely on them). If something breaks after enabling: F12 → Console shows "Refused to load…" — add the affected domain after script-src / img-src.

# BEGIN WebForensik CSP
<IfModule mod_headers.c>
    Header always set Content-Security-Policy "default-src 'self'; img-src 'self' data: https:; style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline'; font-src 'self' https: data:; object-src 'none'; frame-ancestors 'self'; base-uri 'self'"
</IfModule>
# END WebForensik CSP

add_action('send_headers', function () {
    header("Content-Security-Policy: default-src 'self'; img-src 'self' data: https:; style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline'; font-src 'self' https: data:; object-src 'none'; frame-ancestors 'self'; base-uri 'self'");
});

✓ How to verify it works: Open page, F12 → Console — no red "Refused to load…" messages. Network tab → first request → Response Header "content-security-policy" visible.

Without a Referrer-Policy the browser sends the full URL of your current page (incl. search terms, usernames in URL params) on every click to the destination site. Privacy-relevant per Art. 5 GDPR. Recommended safe setting: strict-origin-when-cross-origin.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set Referrer-Policy "strict-origin-when-cross-origin"
</IfModule>

⚠ "strict-origin-when-cross-origin" is the modern standard: on cross-domain clicks only your origin (no path/params) is sent — internal clicks include the full URL. Stricter is "no-referrer" (send nothing) but it breaks some analytics tools.

<IfModule mod_headers.c>
    Header always set Referrer-Policy "strict-origin-when-cross-origin"
</IfModule>

add_action('send_headers', function () {
    header('Referrer-Policy: strict-origin-when-cross-origin');
});

✓ How to verify it works: F12 → Network → first request → Response Headers — "referrer-policy: strict-origin-when-cross-origin" must be present.

Without the "X-Content-Type-Options: nosniff" header the browser guesses file types from content — which attackers can exploit (e.g. a HTML file disguised as .jpg is executed as HTML). The fix is one single line.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set X-Content-Type-Options "nosniff"
</IfModule>

⚠ No side effects expected — considered a safe standard and best practice for years.

<IfModule mod_headers.c>
    Header always set X-Content-Type-Options "nosniff"
</IfModule>

add_action('send_headers', function () {
    header('X-Content-Type-Options: nosniff');
});

✓ How to verify it works: F12 → Network → Response Header: "x-content-type-options: nosniff".

Without clickjacking protection your site can be invisibly embedded into a malicious page ("enter your password here" — the click actually lands on your overlayed login form). Fix: set SAMEORIGIN (only your own domain may embed).

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set X-Frame-Options "SAMEORIGIN"
    Header always set Content-Security-Policy "frame-ancestors 'self'"
</IfModule>

⚠ Use both headers: X-Frame-Options for older browsers, frame-ancestors for modern ones. If you already have a CSP, add "frame-ancestors 'self'" there — don’t duplicate.

<IfModule mod_headers.c>
    Header always set X-Frame-Options "SAMEORIGIN"
</IfModule>

add_action('send_headers', function () {
    header('X-Frame-Options: SAMEORIGIN');
});

✓ How to verify it works: F12 → Network → Response Header: "x-frame-options: SAMEORIGIN".

Permissions-Policy controls whether scripts (including third-party) may access camera, microphone, location, motion sensors etc. GDPR-relevant because sensitive device APIs can otherwise be reached unnoticed.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always set Permissions-Policy "camera=(), microphone=(), geolocation=(), payment=(), usb=(), accelerometer=(), gyroscope=(), magnetometer=(), interest-cohort=()"
</IfModule>

⚠ "()" at the end means: no caller (not even your own page) may use this API. If you need geolocation (e.g. a map feature): use geolocation=(self) instead of geolocation=(). "interest-cohort=()" disables Google’s FLoC tracking.

<IfModule mod_headers.c>
    Header always set Permissions-Policy "camera=(), microphone=(), geolocation=(), payment=(), usb=(), interest-cohort=()"
</IfModule>

add_action('send_headers', function () {
    header('Permissions-Policy: camera=(), microphone=(), geolocation=(), payment=(), usb=(), interest-cohort=()');
});

✓ How to verify it works: F12 → Network → Response Header: "permissions-policy" visible.

Third-party cookies (e.g. from Google, Facebook) track visitors across websites. Under GDPR Art. 6 and ePrivacy / national implementations, explicit consent is required BEFORE setting them. Three-step fix: (1) identify which external services set the cookies, (2) remove services you don’t strictly need, (3) for essential services, add a consent banner that loads them only after "Accept".

✓ How to verify it works: Open the site in incognito mode → F12 → Application → Cookies → your-domain.com. BEFORE clicking "Accept" there must be NO cookies from google.com, facebook.com etc. AFTER consent, yes.

Cookies without the "Secure" flag are also sent over unencrypted HTTP — and can be intercepted by anyone on the same WLAN. There’s no reason to omit Secure on HTTPS-only sites.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always edit Set-Cookie "^(.*)$" "$1; Secure" "expr=!(resp('Set-Cookie') -strmatch '*Secure*')"
</IfModule>

⚠ This header appends "; Secure" to cookies that don’t have it yet. Requires Apache 2.4+. The cleaner fix is to correct the code that sets the cookie (PHP: session.cookie_secure=1 in php.ini, or setcookie() with "secure" => true).

add_filter('secure_logged_in_cookie', '__return_true');
add_action('init', function () {
    if (!headers_sent()) {
        @ini_set('session.cookie_secure', '1');
        @ini_set('session.cookie_httponly', '1');
        @ini_set('session.cookie_samesite', 'Lax');
    }
});

✓ How to verify it works: F12 → Application → Cookies → your-domain.com. The "Secure" column should show a checkmark for every cookie.

Cookies without the "HttpOnly" flag can be read by JavaScript — an XSS attacker can steal session cookies and impersonate the logged-in user. Set HttpOnly for all cookies JavaScript doesn’t actively need.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always edit Set-Cookie "^(.*)$" "$1; HttpOnly" "expr=!(resp('Set-Cookie') -strmatch '*HttpOnly*')"
</IfModule>

⚠ Cleaner: set cookies with HttpOnly directly (PHP: setcookie(..., [..., 'httponly'=>true])). Exception: cookies that JS actively reads (e.g. some consent cookies).

@ini_set('session.cookie_httponly', '1');
@ini_set('session.cookie_secure', '1');

✓ How to verify it works: F12 → Application → Cookies → "HttpOnly" column shows checkmarks everywhere (except for deliberately JS-readable cookies like the consent cookie).

Without "SameSite" cookies are sent on requests from foreign sites — the basis of CSRF attacks (a foreign page silently triggers actions in your name because the login cookie travels along). Set SameSite=Lax as a minimum.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always edit Set-Cookie "^(.*)$" "$1; SameSite=Lax" "expr=!(resp('Set-Cookie') -strmatch '*SameSite*')"
</IfModule>

⚠ SameSite=Lax is a good default. Strict is safer but breaks external links (user clicks from Google to your site — cookies are NOT sent, login is lost). None allows cross-site but requires "; Secure".

@ini_set('session.cookie_samesite', 'Lax');
@ini_set('session.cookie_secure', '1');
@ini_set('session.cookie_httponly', '1');

✓ How to verify it works: F12 → Application → Cookies → "SameSite" column should show "Lax" or "Strict" everywhere, not empty.

GDPR-relevant: visitor data (at least IP + User-Agent) is transmitted to servers outside the EU/EEA. Since the Schrems-II ruling (2020) this requires Standard Contractual Clauses + supplementary technical measures AND prior consent. Best fix: replace with EU alternatives where possible.

✓ How to verify it works: Load in incognito mode, F12 → Network → list all requests → check "Domain" column for non-EU servers. After migration no unrequested US domains should load.

Trackers (Google Analytics, Facebook Pixel, …) capture visitors and follow them across multiple sites. Under GDPR Art. 6 and ePrivacy / national implementations, explicit consent is required BEFORE loading the tracker. "Continued scrolling = consent" is NOT acceptable.

✓ How to verify it works: Incognito, load page — BEFORE "Accept": F12 → Network → no requests to google-analytics.com, facebook.com/tr etc. AFTER "Accept", yes.

Only some of your external resources (2 of 6) are protected by SRI. Add integrity attributes to the remaining ones too.

✓ How to verify it works: F12 → Console on page load: no "Failed to find a valid digest" messages. Source: all external <script>/<link> have an integrity attribute.

CAA records (Certification Authority Authorization) define in DNS which Certificate Authorities are allowed to issue certificates for your domain. Without a CAA record an attacker could request a fraudulent certificate for your domain at any CA. CAA is pure DNS configuration — set in your registrar/DNS-panel, NOT in WordPress.

Name   Type   Flag   Tag      Value
@      CAA    0      issue    "digicert.com"
@      CAA    0      issue    "letsencrypt.org"
@      CAA    0      iodef    "mailto:security@your-domain.com"

✓ How to verify it works: On https://www.ssllabs.com/ssltest/analyze.html?d=your-domain.com → "DNS CAA" section → all your CAs should be listed. Or via dig: dig CAA your-domain.com.

SPF (Sender Policy Framework) defines in DNS which servers may send emails on behalf of your domain. Without SPF any phisher can spoof emails from you — and recipients are more likely to fall for them.

✓ How to verify it works: dig TXT your-domain.com | grep spf — or online https://www.kitterman.com/spf/validate.html.

DMARC combines SPF and DKIM into an explicit instruction for receiving mail servers: "What to do if emails claim to come from us but SPF/DKIM fail?" Without DMARC each server decides — usually generously. With DMARC=reject you effectively prevent phishing in your name.

✓ How to verify it works: dig TXT _dmarc.your-domain.com — or online https://dmarcian.com/dmarc-inspector/.

A security.txt (RFC 9116) tells security researchers how to responsibly report vulnerabilities to you. Without it, reports may go to spam or never be sent. A plain text file at the correct path is enough.

Apache server (classic hosting at most providers)

File: /.well-known/security.txt (create the folder if it doesn’t exist)

Contact: mailto:security@your-domain.com
Expires: 2027-12-31T23:59:59.000Z
Preferred-Languages: en, de
Canonical: https://your-domain.com/.well-known/security.txt

⚠ Replace "security@your-domain.com" with your actual security contact (or a generic info@). "Expires" must be a future date and should be renewed regularly. The file is plain .txt, not PHP.

Contact: mailto:security@your-domain.com
Expires: 2027-12-31T23:59:59.000Z
Preferred-Languages: en, de
Canonical: https://your-domain.com/.well-known/security.txt

✓ How to verify it works: Open https://your-domain.com/.well-known/security.txt in a browser — content must be visible (no 404).

Network Error Logging (NEL) reports network errors to an external server. As with external reporting: mention in privacy policy and verify GDPR compliance of the recipient.

Apache server (classic hosting at most providers)

File: .htaccess in the web root

<IfModule mod_headers.c>
    Header always unset NEL
    Header always unset Report-To
</IfModule>

⚠ If you don’t actively need NEL: these two lines remove both reporting headers. If you do: document it in the privacy policy.

<IfModule mod_headers.c>
    Header always unset NEL
    Header always unset Report-To
</IfModule>

✓ How to verify it works: F12 → Network → first request → Response Header: NO "nel" or "report-to" anymore (or deliberately documented).

Your site sends error or CSP reports to an external service (Report-To: a.nel.cloudflare.com). GDPR-relevant: at least IP address and URL are transmitted. Verify (a) the recipient is GDPR-compliant, (b) the transfer is mentioned in your privacy policy, (c) a data processing agreement (DPA) exists.

✓ How to verify it works: Privacy policy contains an entry about error reporting + DPA is in place. In incognito: F12 → Network → no unintended reporting requests.

Your trackers are loaded BEFORE the user can consent ("pre-consent loading"). Common misconfiguration in cookie plugins — banner appears, but too late: the GA script is already running. Violates ePrivacy.

✓ How to verify it works: Incognito → F12 → Network (clear all, start recording) → load page, do NOT click banner, wait 10 seconds → there must be NO requests to google-analytics.com, googletagmanager.com, facebook.com/tr, doubleclick.net etc.