Routing Abuse

Exposing routes

Exposing the relevant interfaces and parameter information of a Spring application is not a vulnerability, but it can help to understand an application. Moreover, it can be used while checking for access control vulnerabilities, etc.

Check the following routes to see if an application provides path and parameter information:

Additionally, check the following Spring Boot Actuators-related routes which can expose interface address information (but not parameter-related information):

References:

• Spring Boot Vulnerability Exploit Check List: Leakage of routing address and interface call details

Path traversal with /..;/

Spring Boot > 2.2.6 treats https://website.com/allowed/..;/internal same as https://website.com/allowed/../internal.

This can lead to inconsistency between Spring and middleware. For instance, if an application is deployed behind nginx, you can bypass restrictions on allowed paths. Assume nginx forward all request to /allowed/ to an application and deny other requests. In this case, a request to /allowed/../internal will be blocked, however, /allowed/..;/internal is not - nginx will pass it as is to an application and it will hit /internal.

References:

• @0xsapra tweet

useSuffixPatternMatch misconfiguration

Spring Framework versions < 5.3 have a setting called useSuffixPatternMatch (deprecated at 5.2.4). It enables suffix pattern matching that is set to true by default. It means that methods mapped to /adminURL would also match /adminURL[.].*. As a result, it may lead to a potential bypass of URL filters and allow access to restricted areas.

References:

• @ptswarm tweet