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GHSA-2p3x-qw9c-25hh

HighCVSS 7.5 / 10
Published Mar 22, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

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

If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.

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-2021-21341.

Credits

The vulnerability was discovered and reported by threedr3am.

For more information

If you have any questions or comments about this advisory:

Risk Scores
Base Score
7.5

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the availability of the system.

Threat Intelligence
6.9

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
77.80%

The exploit probability is very high. The vulnerability is very likely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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