The Inevitability of Failure: The Flawed Assumption of Security in Modern Computing Environments

1. The Inevitability of Failure: The Flawed Assumption of Security in Modern Computing Environments presented by Toby

4. Introduction

6. IntroductionPremise • Ppl be debating lots of security additions • without much talk about the operating systems

7. IntroductionPremise • Ppl be debating lots of security additions • without much talk about the operating systems • Debates are flawed—assume that application level security can be attained • on current operating systems

8. IntroductionPremise • Ppl be debating lots of security additions • without much talk about the operating systems • Debates are flawed—assume that application level security can be attained • on current operating systems • Current (err.. 15 year old) operating systems are inadequate • from a security standpoint

9. 2 The Missing Link

10. 2 The Missing Link • Mandatory Security • Trusted Path

11. 2 The Missing LinkMandatory Security • Mandatory Security: • “...any security policy where the definition of the policy logic and the assignment of security attributes is tightly controlled by a system security policy administrator.” –this paper • The user should have no influence over the security policy • in theory

12. 2 The Missing LinkMandatory Security • Example systems that should have Mandatory Security: • access control • authentication usage • cryptographic usage

13. 2 The Missing LinkMandatory Security • According to the big black box, Mandatory Security has these general benefits: • Confinement of applications (from a security standpoint) • Lack of burden on individual users to manage security • Narrowing of bandwidth of channels for leaking private information • Increased accountability of unauthorized private information flow

14. 2 The Missing LinkMandatory Security • Example of 1998 state of OSes • Windows NT: • Two security domains: • Complete Privilege • Complete Unprivileged • Pretty coarse-grained

15. 2 The Missing LinkTrusted Path • “A trusted path is a mechanism by which a user may directly interact with trusted software, which can only be activated by either the user or the trusted software and may not be imitated by other software.” –this paper

16. 2 The Missing LinkTrusted Path • “A trusted path is a mechanism by which a user may directly interact with trusted software, which can only be activated by either the user or the trusted software and may not be imitated by other software.” –this paper

17. 2 The Missing LinkTrusted Path • Example given: • Windows NT: • Trusted path given for stuff like password changing • But no means for extending to other trusted software

18. 3 General Examples

19. 3 General ExamplesAccess Control

20. 4 Concrete Examples

21. 4 Concrete ExamplesMobile Code • Mobile code probably meant something much different in 1998 • Here: Java • Mobile = portable • Does not equal iPhone

22. 4 Concrete ExamplesMobile Code • Java (1998): • “not tamperproof or unbypassable” • i.e. you can break boundaries of abstraction • depends on the application-space access control for security • e.g. executables could be tampered with

23. 4 Concrete ExamplesKerberos • Malicious software could spoof client-side authentication • Need a trusted path to guarantee this can’t happen • Client’s password could be obtained

24. 4 Concrete ExamplesKerberos • Malicious software could spoof client-side authentication • Need a trusted path to guarantee this can’t happen • Client’s password could be obtained

25. 6 Summary

26. 6 Summary • No single security mechanism will be a solution to security problems • but we knew that • Modern (1998) computing threats cannot be addressed without secure operating systems • they were right • Authors hoped to motivate interest in OS security • well, people are interested • don’t know if it’s their doing or not