CVE-2021-39150 : What You Need to Know

XStream is a simple library used for serializing objects to XML and vice versa. This CVE presents a Server-Side Request Forgery vulnerability in XStream through PriorityQueue unmarshaling.

Understanding CVE-2021-39150

This section provides insights into the vulnerability and its impact.

What is CVE-2021-39150?

XStream, when operating in affected versions, allows a remote attacker to access internal resources by manipulating the input stream with specific Java runtime versions. Users who have implemented XStream's security framework with whitelists are not affected.

The Impact of CVE-2021-39150

The vulnerability scores 8.5 (High) on the CVSS scale due to its severe impacts:

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

Technical Details of CVE-2021-39150

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The flaw arises from the mishandling of data deserialization, leading to the SSRF risk.

Affected Systems and Versions

Product: XStream
Vendor: X-Stream
Affected Version: < 1.4.18

Exploitation Mechanism

Attackers can exploit this vulnerability remotely via network connections.

Mitigation and Prevention

Discover the steps to mitigate the risks posed by CVE-2021-39150.

Immediate Steps to Take

Upgrade XStream to version 1.4.18 or higher.
Implement whitelists in XStream's security framework.

Long-Term Security Practices

Regularly update XStream to the latest versions.
Perform security audits to identify and rectify vulnerabilities.

Patching and Updates

Follow vendor advisories for patch releases.
Stay informed about security alerts and updates from trusted sources.