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XStream is vulnerable to an attack using Regular Expression for a Denial of Service (ReDos)

Moderate severity GitHub Reviewed Published Mar 13, 2021 in x-stream/xstream • Updated Feb 1, 2023

Package

maven com.thoughtworks.xstream:xstream (Maven)

Affected versions

< 1.4.16

Patched versions

1.4.16

Description

Impact

The vulnerability 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.

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-2021-21348.

Credits

The vulnerability was discovered and reported by threedr3am.

For more information

If you have any questions or comments about this advisory:

References

@joehni joehni published to x-stream/xstream Mar 13, 2021
Reviewed Mar 22, 2021
Published to the GitHub Advisory Database Mar 22, 2021
Published by the National Vulnerability Database Mar 23, 2021
Last updated Feb 1, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS score

1.511%
(87th percentile)

Weaknesses

CVE ID

CVE-2021-21348

GHSA ID

GHSA-56p8-3fh9-4cvq

Source code

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