Domain History

gmx.net

Grade D · 52/100 · 6/7 security headers present

Security Score

52/ 100

Security Headers

6/ 7

CSP Violations

NoViolations

Issues Found

36Issues

Recommendations

3Available

Security

52 / 100

Moderate security gaps found — unsafe directives or weak source restrictions.

Compliance

87 / 100

Mostly compliant but some directives or headers are missing.

Best Practices

43 / 100

Few best practices adopted — significant room for improvement.

CSP Analysis

Content Security PolicyHIGH

connect-src gmx.net *.gmx.net *.adition.com *.mam.dev *.netid.de *.server.lan *.ui-portal.de *.uicdn.com *.uimserv.net united-infos.net; style-src 'unsafe-inline' gmx.net *.gmx.net *.ui-portal.de *.uicdn.com *.gmx.net; script-src 'unsafe-inline' 'unsafe-eval' gmx.net *.gmx.net *.ui-portal.de *.uicdn.com *.uimserv.net united-infos.net; object-src 'none'; form-action *.gmx.at *.gmx.ch gmx.net *.gmx.net; frame-src *.gmx.at *.gmx.ch gmx.net *.gmx.net *.ergebnis-dienst.de *.ui-portal.de *.uimserv.net united-infos.net *.nativendo.de; sandbox allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation; frame-ancestors 'self' www.united-internet-media.de adimg.uimserv.net advideo.uimserv.net; img-src * data:; default-src 'self'; font-src data: *.ui-portal.de

Directive Analysis

connect-srcHIGH

gmx.net *.gmx.net *.adition.com *.mam.dev *.netid.de *.server.lan *.ui-portal.de *.uicdn.com *.uimserv.net united-infos.net

•Subdomain wildcard '*.gmx.net' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.adition.com' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.mam.dev' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.netid.de' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.server.lan' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.ui-portal.de' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uicdn.com' in connect-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uimserv.net' in connect-src - vulnerable to subdomain takeover

style-srcHIGH

unsafe-inline gmx.net *.gmx.net *.ui-portal.de *.uicdn.com *.gmx.net

•Duplicate value '*.gmx.net' in style-src directive

•Unsafe inline execution allowed in style-src

•Subdomain wildcard '*.gmx.net' in style-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.ui-portal.de' in style-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uicdn.com' in style-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.gmx.net' in style-src - vulnerable to subdomain takeover

script-srcHIGH

unsafe-inline unsafe-eval gmx.net *.gmx.net *.ui-portal.de *.uicdn.com *.uimserv.net united-infos.net

•Unsafe inline execution allowed in script-src

•Unsafe eval() execution allowed in script-src

•Subdomain wildcard '*.gmx.net' in script-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.ui-portal.de' in script-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uicdn.com' in script-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uimserv.net' in script-src - vulnerable to subdomain takeover

•No nonces or hashes used for script-src

object-srcLOW

none

form-actionHIGH

*.gmx.at *.gmx.ch gmx.net *.gmx.net

•Subdomain wildcard '*.gmx.at' in form-action - vulnerable to subdomain takeover

•Subdomain wildcard '*.gmx.ch' in form-action - vulnerable to subdomain takeover

•Subdomain wildcard '*.gmx.net' in form-action - vulnerable to subdomain takeover

frame-srcHIGH

*.gmx.at *.gmx.ch gmx.net *.gmx.net *.ergebnis-dienst.de *.ui-portal.de *.uimserv.net united-infos.net *.nativendo.de

•Subdomain wildcard '*.gmx.at' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.gmx.ch' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.gmx.net' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.ergebnis-dienst.de' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.ui-portal.de' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.uimserv.net' in frame-src - vulnerable to subdomain takeover

•Subdomain wildcard '*.nativendo.de' in frame-src - vulnerable to subdomain takeover

sandboxLOW

allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation

frame-ancestorsLOW

self www.united-internet-media.de adimg.uimserv.net advideo.uimserv.net

img-srcHIGH

* data:

•CRITICAL: Bare wildcard (*) in img-src allows ANY source

•Info: 'data:' URI in img-src

default-srcLOW

self

font-srcMEDIUM

data: *.ui-portal.de

•Info: 'data:' URI in font-src

•Subdomain wildcard '*.ui-portal.de' in font-src - vulnerable to subdomain takeover

Missing Directives

⚠HIGHMissing HIGH directive base-uri (Base URI control - prevents base tag injection)

Security Headers

✗Cross-Origin-Opener-PolicyMissing

Isolates the browsing context to prevent Spectre-type side-channel attacks and cross-origin window manipulation.

How to add it:

nginx

add_header Cross-Origin-Opener-Policy "same-origin" always;

apache

Header always set Cross-Origin-Opener-Policy "same-origin"

cloudflare

Rules > Transform Rules > HTTP Response Header Modification > Set Cross-Origin-Opener-Policy to "same-origin"

✓Permissions-PolicyPresent

microphone=(), camera=(), geolocation=(), usb=()

Restricts which browser features (camera, microphone, geolocation) the page can use, limiting attack surface.

✓Referrer-PolicyPresent

strict-origin-when-cross-origin

Controls how much referrer information is sent with requests, preventing data leaks to third parties.

✓Strict-Transport-SecurityPresent

max-age=31536000; includeSubdomains; preload

Forces browsers to use HTTPS for all future requests, preventing man-in-the-middle attacks and SSL stripping.

✓X-Content-Type-OptionsPresent

nosniff

Prevents browsers from MIME-sniffing responses away from the declared Content-Type, blocking drive-by downloads.

✓X-Frame-OptionsPresent

DENY

Prevents the page from being embedded in iframes, protecting against clickjacking attacks.

✓X-XSS-ProtectionPresent

Legacy XSS filter for older browsers. Modern browsers use CSP instead. Set to "0" to avoid false positives.

1 recommended security header is missing on gmx.net.

Issues Found

•CRITICAL: Bare wildcard (*) in img-src allows ANY sourcecritical
•Duplicate value '*.gmx.net' in style-src directiveinfo
•Info: 'data:' URI in font-srcinfo
•Info: 'data:' URI in img-srcinfo
•Missing HIGH directive base-uri (Base URI control - prevents base tag injection)high
•Missing security header: Cross-Origin-Opener-Policymedium
•No nonces or hashes used for script-srcmedium
•Subdomain wildcard '*.adition.com' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ergebnis-dienst.de' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.at' in form-action - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.at' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.ch' in form-action - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.ch' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.net' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.net' in form-action - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.net' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.net' in script-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.gmx.net' in style-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.mam.dev' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.nativendo.de' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.netid.de' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.server.lan' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ui-portal.de' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ui-portal.de' in font-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ui-portal.de' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ui-portal.de' in script-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.ui-portal.de' in style-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uicdn.com' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uicdn.com' in script-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uicdn.com' in style-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uimserv.net' in connect-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uimserv.net' in frame-src - vulnerable to subdomain takeovermedium
•Subdomain wildcard '*.uimserv.net' in script-src - vulnerable to subdomain takeovermedium
•Unsafe eval() execution allowed in script-srchigh
•Unsafe inline execution allowed in script-srchigh
•Unsafe inline execution allowed in style-srchigh

Recommendations

→Add base-uri directive with appropriate restrictions
→Consider implementing a stricter Content Security Policy
→Replace wildcards (*) with specific source lists

Beyond headers: infrastructure exposure

via OSN, our sister project

Security headers protect the browser. OSN maps what's exposed underneath — servers, open ports, known CVEs, DNS and WHOIS.

See what the internet sees about gmx.netWeak headers often come with other exposure — check the full picture.

See full exposure report on OSN →Free, no signup.

gmx.net

2 scans since 6/15/2026

Latest: 52/100

Total Scans

Latest Score

52/100

First Scan

6/15/2026

Last Scan

7/17/2026

Security

52 / 100

Moderate security gaps found — unsafe directives or weak source restrictions.

Compliance

87 / 100

Mostly compliant but some directives or headers are missing.

Best Practices

43 / 100

Few best practices adopted — significant room for improvement.

Score Trend

Security score progression over 2 scans

Scan History

Date	Score	CSP	Headers	Issues	Action
Jul 17, 2026	D (52)	Yes	6/7	36	View →
Jun 15, 2026	D (52)	Yes	6/7	36	View →

Show off your security grade

Embed this badge on your site or README. It updates automatically after each scan and links back to this report.

HeaderTest security grade: D (52/100) for gmx.net

HTML

<a href="https://headertest.com/results/gmx.net" title="Security headers grade for gmx.net — HeaderTest">
  <img src="https://headertest.com/api/badge/gmx.net" alt="HeaderTest security grade: D (52/100) for gmx.net" />
</a>

Markdown

[![HeaderTest security grade: D (52/100) for gmx.net](https://headertest.com/api/badge/gmx.net)](https://headertest.com/results/gmx.net)