BsidesSF 2014 Fix What Matters
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The document criticizes the Common Vulnerability Scoring System (CVSS) for prioritizing vulnerabilities based on theoretical models rather than empirical data. It argues that CVSS suffers from analytical and empirical failures, and proposes using a large dataset of vulnerabilities, exploits, and breaches to establish a more accurate prioritization framework. The framework would calculate the probability that an open vulnerability will be exploited based on observed breach data, in order to focus remediation on the vulnerabilities that pose the greatest actual risk.
BsidesSF 2014 Fix What Matters
- 1. Fix What Matters: ! Why CVSS Sucks And How To Do Better
- 2. Michael Roytman qualifications: Proud Owner of Remote Controlled Airplane Recently a Naive Grad Student Once Jailbroke an Iphone 3G Data Scientist, Risk I/O Does Not Wake Up Before 11 CST
- 3. PART 1: ! YOU SUCK AT YOUR JOB ! (and dont even know it yet)
- 4. Why Are We Here? Analytical Failures of CVSS Empirical Failures of CVSS Proper Remediation Frameworks (Yeah, they exist) CVSS SUCKS (+Data Driven Alternatives)
- 5. Remediation Accept the Risk Repair the Vulnerability Remove the Threat
- 6. C(ommon) V(ulnerability) S(coring) S(ystem) Exploitability/Temporal (Likelihood) Impact/Environmental (Severity) CVSS is designed to rank information system vulnerabilities The Good: Open, Standardized Scores
- 7. It is a capital mistake to theorize before one has data. ! ! ! Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts.
- 8. FAIL: Data Fundamentalism Dont Ignore What a Vulnerability Is: Creation Bias http://blog.risk.io/2013/04/data-fundamentalism/ ! Jerico/Sushidude @ BlackHat https://www.blackhat.com/us-13/briefings.html#Martin ! Luca Allodi - CVSS DDOS http://disi.unitn.it/~allodi/allodi-12-badgers.pdf
- 9. F1: Data Fundamentalism Since 2006 Vulnerabilities have declined by 26 percent. http://csrc.nist.gov/groups/SNS/rbac/documents/vulnerability-trends10.pdf ! ! The total number of vulnerabilities in 2013 is up 16 percent so far when compared to what we saw in the same time period in 2012. http://www.symantec.com/content/en/us/enterprise/other_resources/bintelligence_report_06-2013.en-us.pdf
- 10. FAIL 2: A Priori Modeling Following up my previous email, I have tweaked my equation to try to achieve better separation between adjacent scores and to have CCC have a perfect (storm) 10 score...There is probably a way to optimize the problem numerically, but doing trial and error gives one plausible set of parameters...except that the scores of 9.21 and 9.54 are still too close together. I can adjust x.3 and x.7 to get a better separation . . .
- 11. F3: Logical Inconsistency Temporal Scores Hurt Decision Making Report Confidence is Useless Base Rate Fallacy
- 12. F4: Stochastic Ignorance Attackers Change Tactics Daily
- 14. Empirical Failures of CVSS Objective: Remediate the riskiest vulnerabilities Constraint: Cant measure impact/priority Need: MOAR DATA!!!
- 16. I Love It When You Call Me Big Data 50,000,000 Live Vulnerabilities 1,500,000 Assets 2,000 Organizations
- 17. I Love It When You Call Me Big Data 3,000,000 Breaches
- 18. Baseline Allthethings Probability (You Will Be Breached On A Particular Open Vulnerability)? =(Open Vulnerabilities | Breaches Occurred On Their CVE) /(Total Open Vulnerabilities) 2%
- 19. Probability A Vuln Having Property X Has Observed Breaches RANDOM VULN CVSS 10 CVSS 9 CVSS 8 CVSS 6 CVSS 7 CVSS 5 CVSS 4 Has Patch 0.000 0.010 0.020 0.030 0.040
- 20. PART 2: ! FIX WHAT MATTERS
- 21. Proper Framework Know which vulnerabilities put you most at risk.
- 31. InfoSec?
- 32. Defend Like Youve Done It Before Groups, Motivations Learning from Breaches Asset Topology, Actual Vulns on System Vulnerability De鍖nitions Exploits
- 33. Work With What Youve Got: Akamai, Safenet NVD, MITRE ExploitDB, Metasploit
- 34. Bad Alternatives Why Dont I Just Patch The Important Assets?
- 36. Probability A Vuln Having Property X Has Observed Breaches Random Vuln CVSS 10 Exploit DB Metasploit MSP+EDB 0.0 0.1 0.2 0.2 0.3
- 37. Data Is Everything And Everything Is Data
- 38. Data Is Everything And Everything Is Data
- 39. Be Better Than The Gap
- 40. Data is Everything and Everything is Data Spray and Pray = 2% CVSS 10 = 4% Metasploit and Exploit DB = 30%