This High severity RCE (Remote Code Execution) vulnerability was introduced in version 3.4.6 of Crowd Data Center and Server. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 8.0, allows an authenticated 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 Crowd 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: Crowd Data Center and Server 3.4: Upgrade to a release greater than or equal to 5.1.6 Crowd Data Center and Server 5.2: Upgrade to a release greater than or equal to 5.2.1 See the release notes ([https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html]). You can download the latest version of Crowd Data Center and Server from the download center ([https://www.atlassian.com/software/crowd/download-archive]). This vulnerability was discovered by m1sn0w and reported via our Bug Bounty program.