Symantec has been turning heads with its suggestion that whitelisting might be a better way forward for ensuring the security of PCs than the blacklisting approach that current A/V products, such as those from Symantec, adopt.
My colleagues Jim Rapoza and Larry Seltzer have recently weighed in on the idea: Jim doesn't like it, and Larry is characteristically skeptical of it.
I found it interesting that Jim cited potential discrimination against open-source software as a drawback to application whitelisting, since this is the model around which popular Linux distributions have been modeled for years now.
Linux distributions such as Ubuntu or Foresight or OpenSUSE consist both of core operating system components (alongside a handful of oft-used applications) such as those that ship with Windows, and a library of other, optional applications that sit in networked repositories.
If an application resides in the repositories of your Linux distributor, that piece of software has undergone some sort of vetting process. The vetting differs from distro to distro, and most Linuxes include packages with graduated levels of vetting. Ubuntu Linux, for instance, contains core packages, which enjoy a higher level of testing and support than do its "universe" or "multiverse" packages.
For most distributions, these packaged applications are signed with encryption keys from the distributor, which give users the confidence that the packages are coming from a source they've chosen to trust.
The downside of this application whitelisting approach is that sometimes, the applications or the application versions you want aren't available in your distribution's repositories. In these cases, you must package the applications yourself (and take on the vetting yourself, as well) or turn to others who've done the packaging work (and decide whether to trust those packagers).
Is it a bummer not to be able to install any application you find floating out on the Internet? It depends on how highly you value the integrity of your systems. It's the classic battle of Security vs. Convenience.
One thing's for sure. If you think you can skip through the Internet bending over to pluck and install any shiny app you see, you're going to get bitten.
Is application whitelisting a total solution? I don't think such a thing is possible. However, I contend that traditional A/V cannot, never could and never will clean up after app install promiscuity the way that people wish it would, so better app vetting and a true commitment to least privilege models is the only way forward.
Application whitelisting works for Linux. If Symantec can bring it to Windows, I say more power to them.
What say you?