Arbitrary Code Execution Affecting org.apache.tapestry:tapestry-core package, versions [5.4.0,5.6.2) [5.7.0, 5.7.1)

  • Exploit Maturity

    Proof of concept

  • Attack Complexity


  • Confidentiality


  • Integrity


  • Availability


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  • snyk-id


  • published

    15 Apr 2021

  • disclosed

    15 Apr 2021

  • credit


How to fix?

Upgrade org.apache.tapestry:tapestry-core to version 5.6.2, 5.7.1 or higher.


org.apache.tapestry:tapestry-core is a Tapestry Core package for Apache Tapestry.

Affected versions of this package are vulnerable to Arbitrary Code Execution. A critical unauthenticated remote code execution vulnerability was found in all recent versions of Apache Tapestry.

A bypass of the fix for CVE-2019-0195 exists. where the blacklist solution can simply be bypassed byappending 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 fileAppModule.class is loaded into the response.This class usually contains the HMAC secret key which is used to signserialized Java objects.With the knowledge of that key an attacker can sign a Java gadget chain that leads to RCE.