Headline
CVE-2023-38493: Paths contain matrix variables bypass decorators
Armeria is a microservice framework Spring supports Matrix variables. When Spring integration is used, Armeria calls Spring controllers via TomcatService or JettyService with the path that may contain matrix variables. Prior to version 1.24.3, the Armeria decorators might not invoked because of the matrix variables. If an attacker sends a specially crafted request, the request may bypass the authorizer. Version 1.24.3 contains a patch for this issue.
Package
maven com.linecorp.armeria:armeria (Maven)
Affected versions
<= 1.24.2
Impact
Spring supports Matrix variables.
When Spring integration is used, Armeria calls Spring controllers via TomcatService or JettyService with the path
that may contain matrix variables.
In this situation, the Armeria decorators might not invoked because of the matrix variables.
Let’s see the following example:
// Spring controller
@GetMapping("/important/resources")
public String important() {...}
// Armeria decorator
ServerBuilder sb = ...
sb.decoratorUnder("/important/", authService);
If an attacker sends a request with /important;a=b/resources, the request would bypass the authrorizer
Patches
- https://github.com/line/armeria-ghsa-wvp2-9ppw-337j/commit/9b0ec3e099cc05fbff11d7f1012a1dddb0000d0c
Workarounds
Users can add decorators using regex. e.g. “regex:^/important.*”
Related news
### Impact Spring supports [Matrix variables](https://docs.spring.io/spring-framework/reference/web/webmvc/mvc-controller/ann-methods/matrix-variables.html). When Spring integration is used, Armeria calls Spring controllers via `TomcatService` or `JettyService` with the path that may contain matrix variables. In this situation, the Armeria decorators might not invoked because of the matrix variables. Let's see the following example: ``` // Spring controller @GetMapping("/important/resources") public String important() {...} // Armeria decorator ServerBuilder sb = ... sb.decoratorUnder("/important/", authService); ``` If an attacker sends a request with `/important;a=b/resources`, the request would bypass the authrorizer ### Patches - https://github.com/line/armeria-ghsa-wvp2-9ppw-337j/commit/9b0ec3e099cc05fbff11d7f1012a1dddb0000d0c ### Workarounds Users can add decorators using regex. `e.g. "regex:^/important.*"`