Permissions, Privileges, and Access Controls
Light Display Manager (aka LightDM) 1.4.x before 1.4.3, 1.6.x before 1.6.2, and 1.7.x before 1.7.14 uses 0664 permissions for the temporary .Xauthority file, which allows local users to obtain sensitive information by reading the file.
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.