Improper Control of Generation of Code ('Code Injection')
The DefaultOSWorkflowConfigurator class in Jira Server and Jira Data Center before version 8.18.1 allows remote attackers who can trick a system administrator to import their malicious workflow to execute arbitrary code via a Remote Code Execution (RCE) vulnerability. The vulnerability allowed for various problematic OSWorkflow classes to be used as part of workflows. The fix for this issue blocks usage of unsafe conditions, validators, functions and registers that are build-in into OSWorkflow library and other Jira dependencies. Atlassian-made functions or functions provided by 3rd party plugins are not affected by this fix.
CWE-94 - Code Injection
Code injection is a type of vulnerability that allows an attacker to execute arbitrary code. This vulnerability fully compromises the machine and can cause a wide variety of security issues, such as unauthorized access to sensitive information, manipulation of data, denial of service attacks etc. Code injection is different from command injection in the fact that it is limited by the functionality of the injected language (e.g. PHP), as opposed to command injection, which leverages existing code to execute commands, usually within the context of a shell.