This issue exists to document that a security improvement in the way that Jira Server and Data Center use velocity templates has been implemented.

The way in which velocity templates were used in Atlassian Jira Server and Data Center prior to version 8.8.1 allowed remote attackers to achieve remote code execution via insecure deserialization, if they were able to exploit a server side template injection vulnerability.

Affected versions:

• version < 7.13.0
• 8.0.0 ≤ version < 8.5.0
• 8.6.0 ≤ version < 8.8.1

Fixed versions:

• 8.8.1
• 8.9.0

Workaround for previous versions:
You use this workaround at your own discretion.

1. Download Jira 8.12.3 as zip and extract it’s content
2. Localize your Jira instance installation directory
3. Shutdown your Jira instance
4. Go to the <jira_installation_dir>/atlassian-jira/WEB-INF/lib/ directory
5. Remove files: velocity-htmlsafe-3.0.0.jar and velocity-1.6.4-atlassian-7.jar
6. Copy files velocity-htmlsafe-3.1.1.jar and velocity-1.6.4-atlassian-21.jar from downloaded Jira 8.12 to current directory. They are found in the <Jira_8_12_dir>/atlassian-jira/WEB-INF/lib/ directory
7. Go to the <jira_installation_dir>/atlassian-jira/WEB-INF/classes directory
8. Replace the velocity.properties and velocity-static.properties files with their counterparts from the downloaded Jira 8.12.3
9. Start your Jira instance again