Post on 30-Dec-2015
description
DEEDS Meeting Oct., 26th 2006
Dependable, Embedded Systems and Software GroupDepartment of Computer ScienceDarmstadt University of Technology
Summary of my enquiries made so far…
Daniel Germanus <daniel.germanus@gmail.com>
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
!
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
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
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
DEEDS Meeting Oct., 26th 2006
6
Attack surface (CMU)
•Example for some domain specific attack classes:
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
DEEDS Meeting Oct., 26th 2006
8
IMAPD1 .. Attack surface value is triple <3.5 , 2 , 1.66>
DEEDS Meeting Oct., 26th 2006
9
IMAPD2 .. Attack surface value is triple <5 , 2 , 1.33>
DEEDS Meeting Oct., 26th 2006
10
Threat Index
•Metric with cost/benefit approach
DEEDS Meeting Oct., 26th 2006
11
Threat Index Visualization
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
DEEDS Meeting Oct., 26th 2006
13
Network Attack Graphs
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.
DEEDS Meeting Oct., 26th 2006
15
That‘s it
Thanks.
Please, visit the DEEDS Wiki on Security related content.