StrictHttpFirewall in spring security 4.2 vs spring MVC #MatrixVariable - spring-mvc

Question

Having upgraded to spring security 4.2.4 I discovered that StrictHttpFirewall is now the default.
Unfortunately it doesn't play well with spring MVC #MatrixVariable since ";" are not allowed anymore.
How to get around that?
Example:
#GetMapping(path = "/{param}")
public void example(#PathVariable String param,
#MatrixVariable Map<String, String> matrix) {
//...
}
This could be called like this:
mockMvc.perform(get("/someparam;key=value"))
And the matrix map would be populated.
Now spring security blocks it.
org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String ";"
at org.springframework.security.web.firewall.StrictHttpFirewall.rejectedBlacklistedUrls(StrictHttpFirewall.java:140)
I could use a custom HttpFirewall that would allow semicolons.
Is there a way to use #MatrixVariable without using forbidden characters?
BTW: the javadoc is incorrect https://docs.spring.io/autorepo/docs/spring-security/4.2.x/apidocs/index.html?org/springframework/security/web/firewall/StrictHttpFirewall.html
Since:
5.0.1
I guess it was backported?

Answer 1

You can dilute the default spring security firewall using your custom defined instance of StrictHttpFirewall (at your own risk)
#Bean
public HttpFirewall allowUrlEncodedSlashHttpFirewall() {
StrictHttpFirewall firewall = new StrictHttpFirewall();
firewall.setAllowUrlEncodedSlash(true);
firewall.setAllowSemicolon(true);
return firewall;
}
And then use this custom firewall bean in WebSecurity (Spring boot does not need this change)
#Override
public void configure(WebSecurity web) throws Exception {
super.configure(web);
// #formatter:off
web.httpFirewall(allowUrlEncodedSlashHttpFirewall());
...
}
That shall work with Spring Security 4.2.4+, but of-course that brings some risks!

Answer 2

As mentioned by Крис in a comment if you prefer to use a XML approach, you can add the following part to your securityContext.xml (or whatever your spring-security related xml-config is called):
<bean id="allowSemicolonHttpFirewall"
class="org.springframework.security.web.firewall.StrictHttpFirewall">
<property name="allowSemicolon" value="true"/>
</bean>
<security:http-firewall ref="allowSemicolonHttpFirewall"/>
The <bean> part defines a new StrictHttpFirewall bean with the id allowSemicolonHttpFirewall which is then set as default http-firewall in the <security> tag by referencing the id.

Answer 3

I used combination of following two
https://stackoverflow.com/a/48636757/6780127
https://stackoverflow.com/a/30539991/6780127
First one resolved the
The request was rejected because the URL contained a potentially malicious String ";"
Second one Resolved the
Spring MVC Missing matrix variable
As I am using Spring Security with Spring Web I had to do both And the issue is now Resolved.
I found using #MatrixVariable Following Pattern is useful. First in Url {num} has to be mentioned to use it as #MatrixVariable
#RequestMapping(method = RequestMethod.GET,value = "/test{num}")
#ResponseBody
public ResponseEntity<String> getDetail(#MatrixVariable String num){
return new ResponseEntity<>("test"+num, HttpStatus.OK);
}