There is a command injection vulnerability using environment variables in Bitbucket Server and Data Center. An attacker with permission to control their username can exploit this issue to execute arbitrary code on the system. This vulnerability can be unauthenticated if the Bitbucket Server and Data Center instance has enabled “Allow public signup”.

Multiple API endpoints in Atlassian Bitbucket Server and Data Center 7.0.0 before version 7.6.17, from version 7.7.0 before version 7.17.10, from version 7.18.0 before version 7.21.4, from version 8.0.0 before version 8.0.3, from version 8.1.0 before version 8.1.3, and from version 8.2.0 before version 8.2.2, and from version 8.3.0 before 8.3.1 allows remote attackers with read permissions to a public or private Bitbucket repository to execute arbitrary code by sending a malicious HTTP request. This vulnerability was reported via our Bug Bounty Program by TheGrandPew.

The Microsoft Windows Installer for Atlassian Bitbucket Server and Data Center before version 6.10.9, 7.x before 7.6.4, and from version 7.7.0 before 7.10.1 allows local attackers to escalate privileges because of weak permissions on the installation directory.