cis-nginx-v300-4-1-1

DevOps & Security

Ensure HTTP is redirected to HTTPS (Manual)

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CIS 4.1.1 — Ensure HTTP is redirected to HTTPS

Profile Applicability

Level 1 - Webserver
Level 1 - Proxy
Level 1 - Loadbalancer

Description

Browsers and clients establish encrypted connections with servers by leveraging HTTPS. Requests leveraging HTTP are unencrypted. Unencrypted requests should be redirected so they are encrypted. Any listening HTTP port on your web server should redirect to a server profile that uses encryption. The default HTTP (unencrypted) port is 80.

Rationale

Redirecting user agent traffic to HTTPS helps to ensure all user traffic is encrypted. Modern browsers alert users that your website is insecure when HTTPS is not used. This can decrease user trust in your website and ultimately result in decreased use of your web services. Redirection from HTTP to HTTPS couples security with usability; users are able to access your website even if they lack the security awareness to use HTTPS over HTTP when requesting your website.

Impact

Use of HTTPS does result in a performance reduction in traffic to your website, however, due to the increased value of the security, many businesses consider this to be a cost of doing business.

Audit Procedure

To verify your server listening configuration, check your web server or proxy configuration file. The default web server configuration file is /etc/nginx/conf.d/default.conf, and the default proxy configuration file is /etc/nginx/nginx.conf. The configuration file should return a statement redirecting to HTTPS. This should be similar to the code below, where cisecurity.org is used as an example.

server {
    listen 80;

    server_name cisecurity.org;

    return 301 https://$host$request_uri;
}

Remediation

Edit your web server or proxy configuration file to redirect all unencrypted listening ports, such as port 80, using a redirection through the return directive (cisecurity.org is used as an example server name).

server {
    listen 80;

    server_name cisecurity.org;

    return 301 https://$host$request_uri;
}

Default Value

NGINX is not configured to use HTTPS or redirect to it by default.

References

https://nginx.org/en/docs/http/ngx_http_core_module.html

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.10 Encrypt Sensitive Data in Transit	N	Y	Y
v7	14.4 Encrypt All Sensitive Information in Transit	N	Y	Y

MITRE ATT&CK Mappings

Tactic	Technique
Credential Access	T1557 - Adversary-in-the-Middle
Collection	T1185 - Browser Session Hijacking

Profile

Level 1 - Webserver
Level 1 - Proxy
Level 1 - Loadbalancer