1. DEEDS Meeting Oct., 26th 2006 Dependable, Embedded Systems and Software Group Department of Computer Science Darmstadt University of Technology Summary of my enquiries made so far… Daniel Germanus

2. DEEDS Meeting Oct., 26th 2006 2 Intro Bachelor Thesis was on Threat Modeling Part of Microsofts Security Development Lifecycle Cons can be: – Informal method – Static approach Wanted: – New, or improved attackability measures – Based on exact models – Dynamic system view – (semi) automated !

3. DEEDS Meeting Oct., 26th 2006 3 How to achieve? Enquiries on Security, Metrics, Measures and related Technologies Looking for Metrics, Methods and Tools Metrics: Attack Surface, Risk measurement Methods: Attack Graphs Tools: OPUS In the future: model own metrics or methods

4. DEEDS Meeting Oct., 26th 2006 4 Attack surface (CMU) Definition: Sum of accessible APIs and used resources Non-orthogonal, three dimensional mapping: Targets & Enablers (i.e. resources, processes and data) Channels & Protocols (2 types of channels: message passing and shared memory, every channel associated with a protocol) Access rights: associated with all resources Developed state machine model for System, Threat and User behavior

5. DEEDS Meeting Oct., 26th 2006 5 Attack surface (CMU) Calculating actual attackability … –Relative, not absolute measure –Different approaches possible: Use of domain specific attack classes (cf. Threat Modeling) Definition of own system/channel/data attack classes

6. DEEDS Meeting Oct., 26th 2006 6 Attack surface (CMU) Example for some domain specific attack classes:

7. DEEDS Meeting Oct., 26th 2006 7 Attack surface (CMU) Example for actual metric application Using –two different versions of an IMAP server (IMAPD1 and IMAPD2) –own system/channel/data attack classes

8. DEEDS Meeting Oct., 26th 2006 8 IMAPD1.. Attack surface value is triple

9. DEEDS Meeting Oct., 26th 2006 9 IMAPD2.. Attack surface value is triple

10. DEEDS Meeting Oct., 26th 2006 10 Threat Index Metric with cost/benefit approach

11. DEEDS Meeting Oct., 26th 2006 11 Threat Index Visualization

12. DEEDS Meeting Oct., 26th 2006 12 Network Attack Graphs Per host basis algorithms Supports system analysts, automated graph generation Input parameters are: –a set of host nodes, H –a set of trust relationships, T –a set of access edges, E –a set of network exploits, X –a set of vulnerabilities at each host, V –a new attacker host, h At this stage, only known attacks are considered

13. DEEDS Meeting Oct., 26th 2006 13 Network Attack Graphs

14. DEEDS Meeting Oct., 26th 2006 14 Tools OPUS – Online Patches and Updates for Security –Intention: minimize downtime –Granularity: functions (with identical signature) No globals, no nonrecurring functions (like main), no functions which are currently on some stack frame –Currently only supported for C programs –Validated with several Bugtraq incident reports for buffer overflows, double frees, etc.

15. DEEDS Meeting Oct., 26th 2006 15 That‘s it Thanks. Please, visit the DEEDS Wiki on Security related content.