Jira Data Center & Jira Service Management Data Center - Missing Authentication for Ehcache RMI - CVE-2020-36239

h3. Issue Summary

Jira Data Center, Jira Core Data Center, Jira Software Data Center, and Jira Service Management Data Center exposed a Ehcache RMI network service which attackers, who can connect to the service, on port 40001 and potentially 40011 [0][1][2], could execute arbitrary code of their choice in Jira through deserialization due to a missing authentication vulnerability. While Atlassian strongly suggests restricting access to the Ehcache ports to only Data Center instances, fixed versions of Jira will now require a shared secret in order to allow access to the Ehcache service.

[0] In Jira Data Center, Jira Core Data Center, and Jira Software Data Center versions prior to 7.13.1, the Ehcache object port can be randomly allocated.

[1] In Jira Service Management Data Center versions prior to 3.16.1, the Ehcache object port can be randomly allocated.

[2] The default Ehcache port is 40001 but it can be configured to be on a different port, see [Installing JIRA Data Center|https://confluence.atlassian.com/adminjiraserver/installing-jira-data-center-938846870.html#InstallingJiraDataCenter-parametersCluster.propertiesfileparameters] for more details.

Affected versions:
The versions of Jira Data Center, Jira Core Data Center, and Jira Software Data Center affected by this vulnerability are:

• From version 6.3.0 before 8.5.16 (the fixed version for 8.5.x)
• From version 8.6.0 before 8.13.8 (the fixed version for 8.13.x)
• From version 8.14.0 before 8.17.0

The versions of Jira Service Management Data Center affected by this vulnerability are:

• From version 2.0.2 before 4.5.16 (the fixed version for 4.5.x)
• From version 4.6.0 before 4.13.8 (the fixed version for 4.13.x)
• From version 4.14.0 before 4.17.0

h3. Fixed Versions

To address these issues, we have released Jira Data Center, Jira Core Data Center, and Jira Software Data Center:

• 8.5.16 that contains a fix for this issue
• 8.13.8 that contains a fix for this issue
• 8.17.0 that contains a fix for this issue

Jira Service Management Data Center versions:

• 4.5.16 that contains a fix for this issue
• 4.13.8 that contains a fix for this issue
• 4.17.0 that contains a fix for this issue

These versions can be downloaded at:

• Jira Core Server: [https://www.atlassian.com/software/jira/core/download]
• Jira Software Data Center: [https://www.atlassian.com/software/jira/update]
• Jira Service Management Data Center: [https://www.atlassian.com/software/jira/service-management/update]

h3. Additional details

For additional details, see the full advisory: [https://confluence.atlassian.com/adminjiraserver/jira-data-center-and-jira-service-management-data-center-security-advisory-2021-07-21-1063571388.html]