GHSA-2q8x-2p7f-574v

XStream is vulnerable to an Arbitrary Code Execution attack

### Impact The vulnerability may allow a remote attacker to load and execute arbitrary code from a remote host only by manipulating the processed input stream, if using the version out of the box with Java runtime version 14 to 8 or with JavaFX installed. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. ### Patches XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose. ### Workarounds See [workarounds](https://x-stream.github.io/security.html#workaround) for the different versions covering all CVEs. ### References See full information about the nature of the vulnerability and the steps to reproduce it in XStream's documentation for [CVE-2021-39153](https://x-stream.github.io/CVE-2021-39153.html). ### Credits Ceclin and YXXX from the Tencent Security Response Center found and reported the issue to XStream and provided the required information to reproduce it. ### For more information If you have any questions or comments about this advisory: * Open an issue in [XStream](https://github.com/x-stream/xstream/issues) * Contact us at [XStream Google Group](https://groups.google.com/group/xstream-user)