d4d89f7f422c47fd2de38fffb10ef83b43a0bcca

Oct 13, 2025 by pynkocean.com 8 views

Introduction

In this article, we will discuss the CVE-2020-26259 vulnerability, which is a medium-severity vulnerability detected in the xstream-1.4.5.jar library. This vulnerability is a result of an arbitrary file deletion on the local host when unmarshalling, which can be exploited by a remote attacker to delete arbitrary known files on the host.

CVE-2020-26259 - Medium Severity Vulnerability

Vulnerable Library

The vulnerable library is xstream-1.4.5.jar, which is a Java library used for serializing objects to XML and back again.

Library Home Page

The library home page is located at http://codehaus.org/xstream-parent/xstream/.

Dependency Hierarchy

The dependency hierarchy of the vulnerable library is as follows:

xstream-1.4.5.jar (Vulnerable Library)

Found in HEAD Commit

The vulnerable library was found in the HEAD commit of the SAST-Test-Repo-7af068e8-d0c1-438f-92b7-9b2c8a8f0249 repository, with the commit hash d4d89f7f422c47fd2de38fffb10ef83b43a0bcca.

Found in Base Branch

The vulnerable library was also found in the main branch of the repository.

Vulnerability Details

XStream Vulnerability

XStream is a Java library used for serializing objects to XML and back again. In XStream before version 1.4.15, there is a vulnerability that allows an arbitrary file deletion on the local host when unmarshalling. This vulnerability can be exploited by a remote attacker to delete arbitrary known files on the host, as long as the executing process has sufficient rights.

Impact

The impact of this vulnerability is high, as it can allow a remote attacker to delete arbitrary known files on the host. This can lead to a denial-of-service (DoS) attack or even a complete compromise of the system.

CVSS 3 Score Details

The CVSS 3 score for this vulnerability is 6.8, with the following metrics:

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality Impact: None
Integrity Impact: High
Availability Impact: None

Suggested Fix

The suggested fix for this vulnerability is to upgrade the version of the xstream library to at least 1.4.15. This can be done by updating the pom.xml file to use the latest version of the library.

Conclusion

In conclusion, the CVE-2020-26259 vulnerability is a medium-severity vulnerability detected in the xstream-1.4.5.jar library. This vulnerability can be exploited by a remote attacker to delete arbitrary known files on the host, leading to a denial-of-service (DoS) attack or even a complete compromise of the system. The suggested fix for this vulnerability is to upgrade the version of the xstream library to at least 1.4.15.

Recommendations

Upgrade the version of the xstream library to at least 1.4.15.
Use a whitelist of allowed types to avoid the vulnerability.
Use a workaround described in the referenced advisories for users of XStream 1.4.14 or below who still want to use XStream's default blacklist.

References

CVE-2020-26259: https://www.mend.io/vulnerability-database/CVE-2020-26259
XStream: http://codehaus.org/xstream-parent/xstream/
CVSS 3 Calculator: https://www.first.org/cvss/calculator/3.0
CVE-2020-26259 (Medium) detected in xstream-1.4.5.jar: Q&A =====================================================

Introduction

In our previous article, we discussed the CVE-2020-26259 vulnerability, which is a medium-severity vulnerability detected in the xstream-1.4.5.jar library. In this article, we will answer some frequently asked questions (FAQs) related to this vulnerability.

Q: What is the CVE-2020-26259 vulnerability?

A: The CVE-2020-26259 vulnerability is a medium-severity vulnerability detected in the xstream-1.4.5.jar library. This vulnerability allows an arbitrary file deletion on the local host when unmarshalling, which can be exploited by a remote attacker to delete arbitrary known files on the host.

Q: What is XStream?

A: XStream is a Java library used for serializing objects to XML and back again. It is a popular library used in many Java applications.

Q: What is the impact of this vulnerability?

A: The impact of this vulnerability is high, as it can allow a remote attacker to delete arbitrary known files on the host. This can lead to a denial-of-service (DoS) attack or even a complete compromise of the system.

Q: How can I exploit this vulnerability?

A: To exploit this vulnerability, a remote attacker would need to manipulate the processed input stream to delete arbitrary known files on the host. This can be done by sending a specially crafted XML file to the application that uses XStream.

Q: How can I fix this vulnerability?

A: The suggested fix for this vulnerability is to upgrade the version of the xstream library to at least 1.4.15. This can be done by updating the pom.xml file to use the latest version of the library.

Q: What is the CVSS 3 score for this vulnerability?

A: The CVSS 3 score for this vulnerability is 6.8, with the following metrics:

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality Impact: None
Integrity Impact: High
Availability Impact: None

Q: Is this vulnerability still exploitable in Java 15 or higher?

A: No, this vulnerability is not exploitable in Java 15 or higher.

Q: Can I use a workaround to avoid this vulnerability?

A: Yes, you can use a workaround described in the referenced advisories for users of XStream 1.4.14 or below who still want to use XStream's default blacklist.

Q: What are the recommended steps to fix this vulnerability?

A: The recommended steps to fix this vulnerability are:

Upgrade the version of the xstream library to at least 1.4.15.
Use a whitelist of allowed types to avoid the vulnerability.
Use a workaround described in the referenced advisories for users of XStream 1.4.14 or below who still want to use XStream's default blacklist.

Conclusion

In conclusion, the CVE-2020-26259 vulnerability is a medium-severity vulnerability detected in the xstream-1.4.5.jar library. This vulnerability can be exploited by a remote attacker to delete arbitrary known files on the host, leading to a denial-of-service (DoS) attack or even a complete compromise of the system. We hope that this Q&A article has provided you with the information you need to fix this vulnerability.