Security HTTP Response Headers

You can use Security HTTP Response Headers to increase the security of web applications. This section is dedicated to WebFlux-based support for Security HTTP Response Headers.

Default Security Headers

Spring Security provides a default set of Security HTTP Response Headers to provide secure defaults. While each of these headers are considered best practice, it should be noted that not all clients use the headers, so additional testing is encouraged.

You can customize specific headers. For example, assume that you want the defaults but you wish to specify SAMEORIGIN for X-Frame-Options.

You can do so with the following configuration:

Customize Default Security Headers

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.frameOptions(frameOptions -> frameOptions
				.mode(Mode.SAMEORIGIN)
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            frameOptions {
                mode = Mode.SAMEORIGIN
            }
        }
    }
}

If you do not want the defaults to be added and want explicit control over what should be used, you can disable the defaults:

Disable HTTP Security Response Headers

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers.disable());
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            disable()
        }
    }
}

Cache Control

Spring Security includes Cache Control headers by default.

However, if you actually want to cache specific responses, your application can selectively add them to the ServerHttpResponse to override the header set by Spring Security. This is useful to ensure that such things as CSS, JavaScript, and images are properly cached.

When using Spring WebFlux, you typically do so within your configuration. You can find details on how to do so in the Static Resources portion of the Spring Reference documentation.

If necessary, you can also disable Spring Security’s cache control HTTP response headers.

Cache Control Disabled

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.cache(cache -> cache.disable())
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            cache {
                disable()
            }
        }
    }
}

Content Type Options

By default, Spring Security includes Content-Type headers. However, you can disable it:

Content Type Options Disabled

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.contentTypeOptions(contentTypeOptions -> contentTypeOptions.disable())
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            contentTypeOptions {
                disable()
            }
        }
    }
}

HTTP Strict Transport Security (HSTS)

By default, Spring Security provides the Strict Transport Security header. However, you can customize the results explicitly. For example, the following example explicitly provides HSTS:

Strict Transport Security

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.hsts(hsts -> hsts
				.includeSubdomains(true)
				.preload(true)
				.maxAge(Duration.ofDays(365))
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            hsts {
                includeSubdomains = true
                preload = true
                maxAge = Duration.ofDays(365)
            }
        }
    }
}

X-Frame-Options

By default, Spring Security disables rendering within an iframe by using X-Frame-Options.

You can customize frame options to use the same origin:

X-Frame-Options: SAMEORIGIN

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.frameOptions(frameOptions -> frameOptions
				.mode(SAMEORIGIN)
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            frameOptions {
                mode = SAMEORIGIN
            }
        }
    }
}

X-XSS-Protection

By default, Spring Security instructs browsers to disable the XSS Auditor by using <<headers-xss-protection,X-XSS-Protection header>. You can disable the X-XSS-Protection header entirely:

X-XSS-Protection Customization

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.xssProtection(xssProtection -> xssProtection.disable())
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            xssProtection {
                disable()
            }
        }
    }
}

You can also change the header value:

X-XSS-Protection Explicit header value

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.xssProtection(xssProtection -> xssProtection.headerValue(XXssProtectionServerHttpHeadersWriter.HeaderValue.ENABLED_MODE_BLOCK))
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            xssProtection {
                headerValue = XXssProtectionServerHttpHeadersWriter.HeaderValue.ENABLED_MODE_BLOCK
            }
        }
    }
}

Content Security Policy (CSP)

By default, Spring Security does not add Content Security Policy, because a reasonable default is impossible to know without the context of the application. The web application author must declare the security policies to enforce and/or monitor for the protected resources.

For example, consider the following security policy:

Content Security Policy Example

Content-Security-Policy: script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/

Given the preceding policy, you can enable the CSP header:

Content Security Policy

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.contentSecurityPolicy(policy -> policy
				.policyDirectives("script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/")
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            contentSecurityPolicy {
                policyDirectives = "script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/"
            }
        }
    }
}

To enable the CSP report-only header, provide the following configuration:

Content Security Policy Report Only

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.contentSecurityPolicy(policy -> policy
				.policyDirectives("script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/")
				.reportOnly()
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            contentSecurityPolicy {
                policyDirectives = "script-src 'self' https://trustedscripts.example.com; object-src https://trustedplugins.example.com; report-uri /csp-report-endpoint/"
                reportOnly = true
            }
        }
    }
}

Referrer Policy

Spring Security adds the Referrer Policy header by default with the directive no-referrer. You can change the Referrer Policy header using configuration as shown below:

Referrer Policy Configuration

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.referrerPolicy(referrer -> referrer
				.policy(ReferrerPolicy.SAME_ORIGIN)
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            referrerPolicy {
                policy = ReferrerPolicy.SAME_ORIGIN
            }
        }
    }
}

Feature Policy

By default, Spring Security does not add Feature Policy headers. Consider the following Feature-Policy header:

Feature-Policy Example

Feature-Policy: geolocation 'self'

You can enable the preceding Feature Policy header:

Feature-Policy Configuration

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.featurePolicy("geolocation 'self'")
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            featurePolicy("geolocation 'self'")
        }
    }
}

Permissions Policy

By default, Spring Security does not add Permissions Policy headers. Consider the following Permissions-Policy header:

Permissions-Policy Example

Permissions-Policy: geolocation=(self)

You can enable the preceding Permissions Policy header:

Permissions-Policy Configuration

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	http
		// ...
		.headers(headers -> headers
			.permissionsPolicy(permissions -> permissions
				.policy("geolocation=(self)")
			)
		);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    return http {
        // ...
        headers {
            permissionsPolicy {
                policy = "geolocation=(self)"
            }
        }
    }
}

Clear Site Data

By default, Spring Security does not add Clear-Site-Data headers. Consider the following Clear-Site-Data header:

Clear-Site-Data Example

Clear-Site-Data: "cache", "cookies"

You can send the Clear-Site-Data header on logout:

Clear-Site-Data Configuration

Java
Kotlin

@Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
	ServerLogoutHandler securityContext = new SecurityContextServerLogoutHandler();
	ClearSiteDataServerHttpHeadersWriter writer = new ClearSiteDataServerHttpHeadersWriter(CACHE, COOKIES);
	ServerLogoutHandler clearSiteData = new HeaderWriterServerLogoutHandler(writer);
	DelegatingServerLogoutHandler logoutHandler = new DelegatingServerLogoutHandler(securityContext, clearSiteData);

	http
		// ...
		.logout()
			.logoutHandler(logoutHandler);
	return http.build();
}

@Bean
fun webFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
    val securityContext: ServerLogoutHandler = SecurityContextServerLogoutHandler()
    val writer = ClearSiteDataServerHttpHeadersWriter(CACHE, COOKIES)
    val clearSiteData: ServerLogoutHandler = HeaderWriterServerLogoutHandler(writer)
    val customLogoutHandler = DelegatingServerLogoutHandler(securityContext, clearSiteData)

    return http {
        // ...
        logout {
            logoutHandler = customLogoutHandler
        }
    }
}