Hi, Let me add another complexity dimension in this topic.
Few IDS/IPS vendors can correlate their vulnerability assessment tools with their IDP products (i.e. McAfee,IBM,Tenable,and a few others). None of them however, can link vulnerabilities with exploits and IDP signatures as well, which makes sense since IDP detects attacks (i.e. one or more vulnerabilities exploited in a predefined -not random- order) not plain vulnerabilities. The IDP community -to the best of my knowledge- is still missing a topological-aware mechanism to produce potential attacks based on real vulnerabilities found in systems/networks. To this extend, it is still virtually impossible to eliminate false positives in IDP (learning mode is a nightmare for those who tried, clearly not an option) while it's also extremely hard to eliminate false negatives in VA tools (it would be great if a tool could base verdict upon partially discovered signs of attacks). What seems of interest and what I've been working on this for the last couple of years is to integrate post-incident capabilities (e.g. info from SIEMs) along with vulnerability scoring (like Mitre's CVSS) into IDP/VA tools. This would allow for quite flexible configuration scenarios in IDP, since vulnerabilities are discovered (VA tool) and (semi)automatically scored (CVSS), verified (SIEM information) while a smaller set of signatures (IDP) can detect and block attacks since they can break the predefined order of vulnerability exploit. In other words, such a view could allow for policies based on attack paths and not underlying OS, network topology, collision domains, groups or VLANs. Thanks a lot, Dimitrios Patsos, Ph.D.(Cand),M.Sc.,CCSE,CCDA,CCSP,CME -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Enigma Sent: Tuesday, June 03, 2008 8:44 PM To: Ravi Chunduru Cc: Focus IDS Subject: Re: CVE selection for IDS/IPS signature rules Ravi Chunduru wrote: > Hi, > > There are over 30000 CVE vulnerability reports. Many IDS/IPS devices > have around 4000-5000 signature rules. My guess is that these > signatures may cover (detect)around 4000-7000 attacks. 23000 to 26000 > CVEs, that is, significant number of CVEs are not covered by IDS/IPS > devices. > > I am guessing that there is reason for this. IDS/IPS vendors may be > selecting few CVEs for developing signatures. What is the selection > criteria followed in industry? One criteria, I know is that Network > IDS/IPS devices don't need to worry about attacks that can only be > mounted on the local machine, that is, NIDS/NIPS devices only need to > worry about detection of attacks mounted remotely. Are there any other > considerations? > > Thanks > Ravi > > ------------------------------------------------------------------------ > Test Your IDS > > Is your IDS deployed correctly? > Find out quickly and easily by testing it > with real-world attacks from CORE IMPACT. > Go to http://www.coresecurity.com/index.php5?module=Form&action=impact&campaig n=intro_sfw > to learn more. > ------------------------------------------------------------------------ > > > Couple of things: 1. If you are talking about Network IDS/IPS, not all vulnerabilities are remotely exploitable. Some local vulnerabilities can only be detected by a HIDS if they can be detected at all. 2. Keep in mind that CVE is Common **Vulnerability* *and Exposures, so it covers any vulnerability where IDS/IPS are generally exploit-centric. How are you going to detect if a vulnerability is exploited if there is no publicly known exploit? How do you find something when you don't know what it looks like? ------------------------------------------------------------------------ Test Your IDS Is your IDS deployed correctly? Find out quickly and easily by testing it with real-world attacks from CORE IMPACT. Go to http://www.coresecurity.com/index.php5?module=Form&action=impact&campaig n=intro_sfw to learn more. ------------------------------------------------------------------------ ------------------------------------------------------------------------ Test Your IDS Is your IDS deployed correctly? Find out quickly and easily by testing it with real-world attacks from CORE IMPACT. Go to http://www.coresecurity.com/index.php5?module=Form&action=impact&campaign=intro_sfw to learn more. ------------------------------------------------------------------------
