XStream can cause a Denial of Service

Impact

The vulnerability may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service 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 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-2021-39140.

Credits

The vulnerability was discovered and reported by Lai Han of nsfocus security team.

For more information

If you have any questions or comments about this advisory:

• Open an issue in XStream
• Contact us at XStream Google Group