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. 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-2021-39151
https://x-stream.github.io/CVE-2021-39151.html.
### Credits
Smi1e of DBAPPSecurity WEBIN Lab 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