Bamboo before 6.0.5, 6.1.x before 6.1.4, and 6.2.x before 6.2.1 had a REST endpoint that parsed a YAML file and did not sufficiently restrict which classes could be loaded. An attacker who can log in to Bamboo as a user is able to exploit this vulnerability to execute Java code of their choice on systems that have vulnerable versions of Bamboo.

Atlassian Bamboo 5.x before 5.15.7 and 6.x before 6.0.1 did not correctly check if a user creating a deployment project had the edit permission and therefore the rights to do so. An attacker who can login to Bamboo as a user without the edit permission for deployment projects is able to use this vulnerability, provided there is an existing plan with a green build, to create a deployment project and execute arbitrary code on an available Bamboo Agent. By default a local agent is enabled; this means that code execution can occur on the system hosting Bamboo as the user running Bamboo.