CVE-2022-31692 Demo

Overview

A simple Spring Boot application demonstrating configuration that is vulnerable to CVE-2022-31692.

This vulnerability may attract attention due to its severity - it has a CVSS 3.x base score of 9.8 as it allows authentication bypass. The purpose of this project is to demonstrate the conditions described in the advisory, which lead to the vulnerability being applicable.

• The application expects that Spring Security applies security to forward and include dispatcher types.
• The application uses the AuthorizationFilter either manually or via the authorizeHttpRequests() method.
• The application configures the FilterChainProxy to apply to forward and/or include requests (e.g. spring.security.filter.dispatcher-types = request, error, async, forward, include).
• The application may forward or include the request to a higher privilege-secured endpoint.
• The application configures Spring Security to apply to every dispatcher type via authorizeHttpRequests().shouldFilterAllDispatcherTypes(true)

For reference, I'm pretty sure this is the commit that addresses the vulnerability.

Demonstration

The application has three URLs:

1. / The index page
2. /admin An admin page, which requires the user to provide Basic auth (creds "user"/"pass") and be assigned the ROLE_ADMIN role
3. /forward A server-side forward to the admin page

Access controls are specified via authorizeHttpRequests() in the SecurityConfig class.

.authorizeHttpRequests((authz) -> authz
	.antMatchers("/").permitAll()
	.antMatchers("/forward").permitAll()
	.antMatchers("/admin").hasAuthority("ROLE_ADMIN")
	.shouldFilterAllDispatcherTypes(true)
)

Expected behaviours

1. User accesses / and is not authenticated (thanks to permitAll())

2. User accesses /admin . They don't provide authentication, and the request is rejected (401 Not authorized).

3. User accesses /admin . They provide valid authentication, but the request is still rejected (403 Unauthorised) because they do not have the required role .hasAuthority("ROLE_ADMIN").

4. User accesses /forward. Their requests passes through the security filter chain for GET /forward, which passes as valid (thanks to permitAll()). The controller processes the request, and returns forward:/admin to the Dispatcher. As instructed by the spring.security.filter.dispatcher-types and .shouldFilterAllDispatcherTypes(true) settings, this is a FORWARD type, so should be passed through the filter chain again. This second pass through the filter results in the request being rejected (again, thanks to hasAuthority("ROLE_ADMIN")).

Actual behaviour

User accesses /forward, the request is passed through the filter chain once, and passes as valid. The forward is processed, but instead of being passed through the chain again, it is just passed as valid, and the admin page is returned.