Improper Access Control
Atlassian Bamboo before 22.214.171.124 and 5.12.x before 126.96.36.199 does not properly restrict permitted deserialized classes, which allows remote attackers to execute arbitrary code via vectors related to XStream Serialization.
CWE-284 - Improper Access Control
Listed 5th in the 'OWASP Top Ten', improper (or broken) access control attacks are a fundamental type of vulnerability. This includes a broad range of design flaws that enable users to act outside of their intended permissions. They can use these privileges to gain access to restricted files and functionality such as accessing restricted information, falsifying records, destroying data, or executing commands.