CVE-2021-39140 : What You Need to Know

XStream, a library for object serialization to XML, is vulnerable in versions below 1.4.18, potentially leading to a denial of service attack due to CPU manipulation.

Understanding CVE-2021-39140

XStream's vulnerability in certain versions can result in a denial of service attack due to high CPU usage by manipulating input streams.

What is CVE-2021-39140?

The CVE-2021-39140 vulnerability in XStream allows a remote attacker to exhaust the CPU by manipulating input streams, causing a denial of service.

The Impact of CVE-2021-39140

The vulnerability's impact is rated as MEDIUM severity with a base CVSS score of 6.5. It requires low privileges and no user interaction, leading to a denial of service attack with high availability impact.

Technical Details of CVE-2021-39140

XStream's vulnerability details include:

Vulnerability Description

The issue stems from deserialization of untrusted data, potentially leading to an infinite loop, causing denial of service.

Affected Systems and Versions

Affected Product: XStream
Vendor: x-stream
Versions Affected: < 1.4.18

Exploitation Mechanism

Attack Complexity: LOW
Attack Vector: NETWORK
Scope: UNCHANGED
User Interaction: NONE
Privileges Required: LOW
Availability Impact: HIGH

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2021-39140 vulnerability:

Immediate Steps to Take

Upgrade XStream to version 1.4.18 or higher to patch the vulnerability.
Implement a whitelist security framework to limit deserialization to necessary types.

Long-Term Security Practices

Regularly update software libraries and dependencies.
Monitor and restrict network access to prevent unauthorized exploitation.

Patching and Updates

Keep XStream and related libraries up to date with the latest security patches and releases.