Again, while security guarantees are ideal, they are tough to achieve and tough
to maintain. A better method is to remove all SFI flags in an ActiveX object by default
unless they have been through rigorous security evaluation.
Unmarking Scripts ???Safe for Scripting???
and ???Safe for Initialization???
The easiest way to ensure that ActiveX objects are not scripted or initialized remotely is
not to mark them SFS or SFI. Remove these designations if the control does not need
them. A design review/threat model of how the functionality can be misused, general
fuzzing, and targeted testing should be performed before releasing a control marked
SFS/SFI. Unfortunately, when creating an ActiveX object, you can ensure that the object
is not marked, but hundreds of exiting objects are probably already marked with these
options, and many of them are probably running on your system now. To ensure that no
ActiveX objects are marked with these dangerous options, you can manually remove
these fields by searching through the registry for {7DD95801-9882-11CF-9FA9-
00AA006C42C4} and {7DD95802-9882-11CF-9FA9-00AA006C42C4}. {7DD95801-9882-
11CF-9FA9-00AA006C42C4} notes an ActiveX control is safe for scripting and {7DD95802-
9882-11CF-9FA9-00AA006C42C4} notes the control is ???safe for initialization.
Pages:
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370