Permissions, Privileges, and Access Controls
MediaWiki 1.11, and other versions before 1.13.3, does not properly protect against the download of backups of deleted images, which might allow remote attackers to obtain sensitive information via requests for files in images/deleted/.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.