CVE-2021-21348

Description

From CVE.org

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability which may allow a remote attacker to occupy a thread that consumes maximum CPU time and will never return. 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.

Statement

OpenShift Container Platform (OCP) delivers Jenkins LTS package with bundled XStream library. Due to JEP-200 [1] and JEP-228 [2] Jenkins projects, OCP Jenkins package is not affected by this flaw.

[1] https://github.com/jenkinsci/jep/blob/master/jep/200/README.adoc [2] https://github.com/jenkinsci/jep/blob/master/jep/228/README.adoc#security

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.97.5N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityHighLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Red Hat CVSS v3 Score Explanation

This flaw requires certain classes to be present in the JVM classpath for a successful exploit; the inclusion of these classes is beyond the attacker's control, and we feel is better represented by Access Complexity of High.

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Resource Consumption (CPU)

Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.

Frequently Asked Questions

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