Signal

Below the B minimum (70/100) in our RFP clause. A buyer using it would ask for a dated fix for each missing header.

With these headers missing, signal.org is more exposed to man-in-the-middle attacks, malicious JavaScript, redirected forms, hijacked payments and clickjacking.

Missing 6

• Content-Security-Policy 0 of 25

  Tells the browser which scripts may run on the page, where its forms may submit, and where it may send data.

  Without it: This is the main defence against malicious JavaScript. If an attacker gets any script onto the page (through a bug, a compromised analytics tag, chat widget or ad, or a poisoned package), the browser runs it with the signed-in user's full access. It can capture what they type, quietly point a sign-in or checkout form at the attacker's server, and skim card numbers as they are entered. A strict policy blocks scripts it does not list, and its form-action and connect-src rules leave stolen data nowhere to go.

• Strict-Transport-Security 0 of 20

  Tells browsers to use HTTPS for this domain, every time, without trying plain HTTP first.

  Without it: The site is open to man-in-the-middle attacks. The first request a user makes (typing the domain, following an old http:// link) can go out unencrypted, and anyone on the same network, such as café, hotel or airport Wi-Fi, can intercept it before the redirect to HTTPS. From there they can read passwords, session cookies and card numbers, serve a fake sign-in page, or inject their own JavaScript into the real one.

• Frame protection 0 of 10

  X-Frame-Options or the CSP frame-ancestors directive: decides which sites may show this one inside a frame.

  Without it: Clickjacking. Another site loads the product invisibly in a frame and lines its real buttons up under something the user wants to click, so a signed-in user approves a payment, changes their account email or grants access without seeing it.

• Permissions-Policy 0 of 10

  Switches off browser features the product does not use, such as camera, microphone, location and payments, for the page and anything embedded in it.

  Without it: Any script or iframe on the page, including third-party ads and chat widgets, can ask the user for camera, microphone or location access under the vendor's name.

• Cross-Origin-Opener-Policy 0 of 5

  Cuts the link between the product's window and windows opened by, or opening, other sites.

  Without it: A page that opens the product keeps a handle on its window and can later redirect it to a look-alike sign-in or payment page (tab-nabbing) while the user thinks they are still on the real site. It is also part of the isolation browsers need to defend against Spectre-style attacks.

• Cross-Origin-Resource-Policy 0 of 5

  Tells browsers which sites may load this site's resources.

  Without it: Other sites can pull the product's responses into their own pages, which makes side-channel leaks of what a signed-in user can see easier.

Sent 3

• X-Content-Type-Options 10 of 10

  nosniff

• Referrer-Policy 10 of 10

  strict-origin-when-cross-origin

• No version disclosure 5 of 5

  server: cloudflare

Checked 2026-10-21 at https://signal.org/. Re-checked every 7 days. The grade covers the headers this website sends, not the product’s overall security. How the grade works.