Over the last week I've had two clients who've had computers broken into because their computers were not appropriately patched. One client's Internet-facing server lacked a critical system patch, and the other was exploited by an unpatched client system infected by a "trusted" Web site.
I know at times that I sound like a broken record about this issue, but I've yet to visit a client (and I consult, on average, about three per month) that has acceptable patching practices in place. They all have patch management software, but for various reasons, my spot-check auditing usually reveals significant deficiencies.
[ Related from security news: "New Web attack exploits unpatched IE flaw" | Earlier this week, Microsoft released this year's final set of patches, bringing the total for 2008 to 77 patches ]
A study by Secunia showed that only 1.91 percent of the computers scanned by their Software Inspector product were completely patched. Even worse (see table below), nearly half of the PCs inspected had 11 or more unpatched programs.
0 Insecure Programs 1.91% of PCs
1 - 5 Insecure Programs 30.27% of PCs
6 - 10 Insecure Programs 25.07% of PCs
11+ Insecure Programs 45.76% of PCs
And you have to believe that the people running the Software Inspector program are among the security-savvy.
Why don't people -- and in particular, administrators -- patch properly? First, it's a difficult job to keep on top of. The patches come frequently throughout the week. Microsoft may only release patches on one Tuesday a month, but most vendors release them ad hoc, often without warning. You may hate Patch Tuesday, but I've heard Linux and Apple administrators complaining about how they get their teams together and apply a patch, only to discover yet another new patch the day after, and another the day after that. If you live in that world, Patch Tuesday doesn't seem so bad. And that's only one vendor's software. Add in every software product you have, each with a different patching cycle, and it's a plan for chaos.
Oftentimes, even when using rock-solid patch management software, a certain percentage of upgrades will fail. In my 20-year-plus experience, the problem rate is somewhere between 1 and 5 percent. That means a machine left unpatched and possibly even a visit by tech support to resolve. And all of us have stories of horrible patch recovery problems that took formatting and complete re-installs to resolve.
Some companies have great patch management software, but policies and necessary regression testing mean it could be a month or more until patches are installed.
Solutions for patch pain
Get on top of your patching. If you don't have systemwide patch management software, get some. Make sure to patch everything on the computer: the operating system, large applications, browser add-ons, everything. If someone else is in charge of patching, spot-check their efficiency. Run Secunia's Software Inspector and see what comes up unpatched.
Except in the rarest of cases (e.g., medical devices requiring regulatory approval, etc.), it's no longer acceptable in today's world to wait more than a week or two to apply a critical patch. Internet-facing servers and computers with access to the Internet need to be patched the fastest. Rank assets by criticality and patch the highest risk assets first. If you can't perform thorough regression testing in a timely manner, create a trustworthy rollback strategy and patch away.
If you cannot patch in a timely manner, look into offsetting controls, like IPS solutions and inline patching solutions. My former favorite inline patching solution, BlueLane's PatchPoint, has been acquired by VMware and doesn't appear to be available at the moment. Anti-malware solutions, firewalls, and auditing certainly have their place in any patching strategy. But all these offsetting controls are doomed to eventual failure. Having fully patched software is one of the best things you can do to improve your security posture.
Many readers might find this topic boring, but I plan to keep covering it until I find more clients fully patched than unpatched. Top echelon computer security administrators know that the best computer security comes from doing the boring stuff consistently great.