CVE-2021-21341

XStream can cause a Denial of Service

HIGH
7.5
CVSS Score
Published: March 22, 2021 at 11:40 PM UTC
Updated: October 7, 2026 at 07:17 PM UTC
13 products affected across 6 vendorsDebian LinuxFedoraOnCommand Insight

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Severity
HIGH7.5
Exploit prediction
EPSS 78%
SSVC
No known exploit

Description

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is vulnerability which 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. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.16.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (15)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400CWE-502

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