QID 730165

A critical unauthenticated remote code execution vulnerability was found in Apache Tapestry.
The vulnerability found is a bypass of the fix for CVE-2019-0195.Before the fix of CVE-2019-0195 it was possible to download arbitrary class files from the classpath by providing a crafted asset file URL. An attacker was able to download the file `AppModule.class` by requesting the URL `http://localhost:8080/assets/something/services/AppModule.class` which contains a HMAC secret key. The fix for that bug was a blacklist filter that checks if the URL ends with `.class`, `.properties` or `.xml`. Bypass: Unfortunately, the blacklist solution can simply be bypassed by appending a `/` at the end of the URL: `http://localhost:8080/assets/something/services/AppModule.class/` The slash is stripped after the blacklist check and the file `AppModule.class` is loaded into the response. This class usually contains the HMAC secret key which is used to sign serialized Java objects. With the knowledge of that key an attacker can sign a Java gadget chain that leads to RCE

Affected Versions:
Apache Tapestry 5.4.0 to 5.6.1
Apache Tapestry 5.7.0

QID Detection Logic:(Unauthenticated)
This QID sends a GET request to check the affected version of Apache Tapestry.

Successful exploitation can result in remote code execution