Published on 29/10/15 - Updated on 07/12/16
OpenStack Compute (Nova) before 2014.2.4 (juno) and 2015.1.x before 2015.1.2 (kilo) do not properly apply security group changes, which allows remote attackers to bypass intended restriction by leveraging an instance that was running when the change was made.
CWE-254 (Security Features)
Software security is not security software. Here we're concerned with topics like authentication, access control, confidentiality, cryptography, and privilege management.