This High severity RCE (Remote Code Execution) vulnerability was introduced in version 11.2.0 of Jira Service Management Data Center and Server.

This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 8.1 and a CVSS Vector of CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H allows an unauthenticated attacker to execute arbitrary code which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction.

Atlassian recommends that Jira Service Management Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

• Jira Service Management Data Center and Server 11.2: Upgrade to a release greater than or equal to 11.2.1

See the release notes. You can download the latest version of Jira Service Management Data Center and Server from the download center.

The National Vulnerability Database provides the following description for this vulnerability: ActionServlet.java in Apache Struts 1 1.x through 1.3.10 mishandles multithreaded access to an ActionForm instance, which allows remote attackers to execute arbitrary code or cause a denial of service (unexpected memory access) via a multipart request, a related issue to CVE-2015-0899.