Cisco Unified IP 9900 phones with firmware 9.4(.1) and earlier use weak permissions for unspecified files, which allows local users to cause a denial of service (persistent hang or reboot) by writing to a phone's filesystem, aka Bug ID CSCup90474.
Category : Permissions, Privileges, and Access Controls Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.