CVE-2020-36239 : Exploit Details and Defense Strategies

Jira Data Center, Jira Core Data Center, Jira Software Data Center, and Jira Service Management Data Center versions are affected by a vulnerability that could allow attackers to execute arbitrary code through deserialization due to a missing authentication vulnerability.

Understanding CVE-2020-36239

This CVE involves a security vulnerability in various Atlassian products that could be exploited by attackers to execute arbitrary code.

What is CVE-2020-36239?

CVE-2020-36239 is a vulnerability in Jira Data Center, Jira Core Data Center, Jira Software Data Center, and Jira Service Management Data Center versions that exposes an Ehcache RMI network service, potentially allowing attackers to execute arbitrary code through deserialization.

The Impact of CVE-2020-36239

The vulnerability could be exploited by attackers who can connect to the service on specific ports to execute arbitrary code in Jira due to a missing authentication mechanism.

Technical Details of CVE-2020-36239

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from a missing authentication mechanism in the Ehcache RMI network service, allowing unauthorized users to execute arbitrary code through deserialization.

Affected Systems and Versions

Jira Data Center, Jira Core Data Center, Jira Software Data Center versions from 6.3.0 to 8.17.0
Jira Service Management Data Center versions from 2.0.2 to 4.17.0

Exploitation Mechanism

Attackers can exploit this vulnerability by connecting to the service on specific ports (40001 and potentially 40011) to execute arbitrary code in Jira through deserialization.

Mitigation and Prevention

Protect your systems from CVE-2020-36239 with the following steps:

Immediate Steps to Take

Restrict access to the Ehcache ports to only Data Center instances
Ensure fixed versions of Jira require a shared secret for access to the Ehcache service

Long-Term Security Practices

Regularly update and patch Jira Data Center, Jira Core Data Center, Jira Software Data Center, and Jira Service Management Data Center
Implement network segmentation and access controls to limit exposure to potential attacks

Patching and Updates

Apply the necessary patches and updates provided by Atlassian to address the vulnerability