Comodo Firewall Pro before 3.0 does not properly validate certain parameters to hooked System Service Descriptor Table (SSDT) functions, which allows local users to cause a denial of service (system crash) via (1) a crafted OBJECT_ATTRIBUTES structure in a call to the NtDeleteFile function, which leads to improper validation of a ZwQueryObject result; and unspecified calls to the (2) NtCreateFile and (3) NtSetThreadContext functions, different vectors than CVE-2007-0709.