Symantec Norton Personal Firewall 2006 9.1.0.33, and possibly earlier, does not properly protect Norton registry keys, which allows local users to provide Trojan horse libraries to Norton by using RegSaveKey and RegRestoreKey to modify HKLM\SOFTWARE\Symantec\CCPD\SuiteOwners, as demonstrated using NISProd.dll.  NOTE: in most cases, this attack would not cross privilege boundaries, because modifying the SuiteOwners key requires administrative privileges.  However, this issue is a vulnerability because the product's functionality is intended to protect against privileged actions such as this.