Full Disclosure mailing list archives
Re: Getting Off the Patch
From: "Cor Rosielle" <cor () outpost24 com>
Date: Thu, 13 Jan 2011 09:48:43 +0100
I am not responding solely on the opinions in the emails. I actually know what is in the OSSTMM. Let me start by saying that patching is not bad in itself. It can be a good solution. It can even be the only solution. It can also be necessary to patch a piece of software. And the OSSTMM won't tell you different. As Pete's article reads, patching is just a small part of the solution. One of the things with patches is, that people have an urge to apply them. Vic wrote: "... if there is software installed on a system and that software has a known vulnerability and an available patch, any smart resource owner is going to mandate that the patch be applied to mitigate "potential" risk.". Even if we doubt the patch will affect our system, we are often uncertain what will happen if we don't apply the patch. Because we fear the audit, we decide to cover our ass and apply the patch. Not because it will make the system more safe, but because it will keep us from trouble. We even install unnecessary patches, like a fix in mod_ssl where you're not using SSL in the first place. Fear, uncertainty and doubt do not help in being objective about the solution. Most people don't realize the automated download and installation processes can be attacked. There are even tools available to do so. Through such an attack you might be applying a malicious or poisoned update on 800 of your servers. When you follow the OSSTMM, you see this involves an access and a trust, which both need to be controlled. Patching is often considered necessary for passing an audit. The bad thing is that auditors often don't understand a bit about security. By identifying controls in several organizations they came up with a list of standards, often called "best practices". And then they just check that list to see if your company complies to the "security standard". But those best practices is nothing more than a list of safety controls that were used by some other companies, operating under different circumstances than you are and at another time in history. In the best case there is some evidence the control really did provide protection. The fact is that best practices can have some value. Most of the time it is where people don't care to think what is best and just want to be compliant to something and pass the audit. Perhaps they do care but don't understand that being compliant is different from being safe and focus on compliancy. When you follow the OSSTMM you can get some understanding to see how much a best practice will increase (or decrease) your safety. It can help you to decide to accept risks, simply because the control is more expensive than the damage will be when you don't apply that best practice. As Pete's article reads, patching is just a small part of the solution. Following the OSSTMM you will get a good idea where the strong and weak spots are in your systems and how to determine that. The method perfectly scales, because it can tell you about level of safety of a single system, a group of systems belonging together and even all systems in the entire organization, no matter if there are 10, 100, 1000 or more. The OSSTMM is not a list of good or bad things. It is not a list of controls you have to apply and it does not take any decision for you. It just helps you to identify the good and bad things in your environment, how to rate those good and bad things, find the strong and weak areas in protection and assist you in predicting how well a new safety control will actually increase the overall safety. Cor Rosielle Chief Technology Officer
-----Original Message----- From: full-disclosure-bounces () lists grok org uk [mailto:full- disclosure-bounces () lists grok org uk] On Behalf Of Vic Vandal Sent: woensdag 12 januari 2011 20:37 To: full-disclosure () lists grok org uk Subject: Re: [Full-disclosure] Getting Off the Patch While this idea may work in small shops, it won't scale to large ones. There are something like 800 heterogeneous servers where I work. Small clusters of like-purpose servers are allocated to hosting many different processing components that make up the enterprise architecture. Applying purpose-specific hardening is a goal, but one that is extremely difficult to achieve and then maintain. And at the end of the day if you have a server cluster hosting MS-SQL or Oracle or Apache or IIS or whatever, AND only the necessary listening services are on, AND there is filtering to allow specific source and destination traffic, IF there's an identified vulnerability in any of those available services the machines must be patched to mitigate system and data risk. Even with services/daemons/etc. that aren't used and have been disabled, you can't rely on them remaining that way. Some newly installed component could require starting them up, or some Sys-Admin could make a configuration mistake and start up some vulnerable service(s). So if there is software installed on a system and that software has a known vulnerability and an available patch, any smart resource owner is going to mandate that the patch be applied to mitigate "potential" risk. If they don't and the system and/or data is compromised, that resource owner might have a hard time explaining how due diligence was exercised to absolve themselves and the organization of any data breach or service delivery liability. As for having to spend a lot of cycles testing patches, those days of half of the patches being applied breaking something are long gone. The risk still exists, and maybe one or two out of every hundred operating system or core software patches does break something. Vendors have gotten a LOT better about releasing reliable patches. I say this as an InfoSec engineer who has been playing this patching game for 20 years. But what about that small percentage of patches that does break something? For mission-critical servers any organization worth its salt has a Dev, QA, and Production server environment. You roll out the patches to Dev, and make sure nothing breaks while the developers are working daily in that environment. Then you roll to QA and have someone test any app that could potentially be impacted by the patch(es) deployed. By the time you roll the patches to Production, the risk of an outage is almost nil. And for the workstation environment, create a pilot group for patch deployments. Deploy patches to their machines, see if anything breaks, and if nothing does you then deploy the patches safely to the entire organization. As for the cost of deploying patches and the time it takes, automated patching tools are quite mature and robust these days. It takes a security administrator, server administrator, or desktop administrator mere minutes and a few mouse clicks to deploy patches to hundreds or thousands of machines. The other side of this patching coin is being audited. Many organizations are mandated to have independent security audits of their infrastructure performed. Those organizations and others may also have business partners who want audit verification of how vulnerabilities are being mitigated. And where an independent audit report shows that an organization isn't applying patches for countless vulnerabilities on scores of systems, you can bet that the concept and practice of patching will be embraced very soon thereafter. Just for clarity I'm not saying the proposed idea has no value. I'm a big fan of system hardening via various means. If you're not running a vulnerable service or it's not available to untrusted machines or users, the chances of it being compromised are obviously diminished greatly. But you shouldn't rely on that situation remaining static, and the smart move is to patch vulnerable software or remove it from the system altogether if it isn't needed. Obviously removal isn't an option when it comes to operating systems. You could replace them with some B1 certified security level system, but you're not going to be able to run a lot of common business apps successfully on such an architecture. And even if you could those apps could have vulnerabilities and need to be patched. Sandboxing has value, but it doesn't supplant patching in my professional opinion. I do know a way to do away with patching - have software developers stop writing crappy code that doesn't do good input validation (cough). Of course that is a nirvana not likely to be seen in our lifetimes. Wow, did I just write an article damn near equal in length to the InfoSec Island one posted that started this thread? Either I have free time to spare or I'm really into the concept of patching known vulnerabilities. Unfortunately for me it's the latter. Peace, Vic _______________________________________________ Full-Disclosure - We believe in it. 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_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Re: Getting Off the Patch, (continued)
- Re: Getting Off the Patch Pete Herzog (Jan 17)
- Re: Getting Off the Patch Pete Herzog (Jan 17)
- Re: Getting Off the Patch Thor (Hammer of God) (Jan 17)
- Re: Getting Off the Patch Григорий Братислава (Jan 17)
- Re: Getting Off the Patch Pete Herzog (Jan 17)
- Re: Getting Off the Patch Thor (Hammer of God) (Jan 17)
- Re: Getting Off the Patch Pete Herzog (Jan 17)
- Re: Getting Off the Patch Roger Casteele (Jan 16)
- Re: Getting Off the Patch Christian Sciberras (Jan 17)
- Re: Getting Off the Patch Cor Rosielle (Jan 13)