The image signature algorithm in OpenStack Glance 11.0.0 allows remote attackers to bypass the signature verification process via a crafted image, which triggers an MD5 collision.

OpenStack Image Service (Glance) before 2015.1.3 (kilo) and 11.0.x before 11.0.2 (liberty), when show_multiple_locations is enabled, allow remote authenticated users to change image status and upload new image data by removing the last location of an image.