HTTP Strict Transport Security (HSTS) header not implemented

OWASP 2013-A5 OWASP 2017-A6 OWASP 2021-A5 OWASP 2019-API7 OWASP PC-C1 CAPEC-217 CWE-523 ISO27001-A.14.1.2 WASC-04 WSTG-CONF-07

The most used web security policy mechanism is HTTP Strict Transport Security (HSTS). This header protects web applications against protocol downgrade attacks and cookie hijacking. This header also restricts the application from using only HTTPS communication. The header won’t allow communications via the insecure HTTP protocol. There are many web applications with the HTTP Strict Transport Security (HSTS) header cannot be recognised. These web applications are being served from not only HTTP but also HTTPS. It also lacks proper implementation of HSTS policy. HTTP Strict Transport Security is a web security policy mechanism to interact with complying user agents such as a web browser using only secure HTTP connections. This header informs the browser that, the site should not be loaded over HTTP. This header automatically converts all the requests to the site from HTTP to HTTPS.


The following is the example of strict transport security header.

        Strict-Transport-Security: max-age=31536000



The main impact under this vulnerability:-

  • As the communication is done via HTTP, the site will be vulnerable to man in the middle attack(MITM).

Mitigation / Precaution

  • Configure your webserver to redirect HTTP requests to HTTPS.
        Strict-Transport-Security: max-age=31536000; includeSubDomains; preload


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