Security Relevancy Analysis on the Registry of Windows NT 4.0 (for Wenliang Du)

Nov 19, 1999

Download: MP4 Video Size: 220.6MB  

Abstract

Many security breaches are caused by inappropriate inputs crafted by people with malicious intents. To enhance the system security, we need either to ensure that inappropriate inputs are filtered out by the program, or to ensure that only trusted people can access those inputs. In the second approach, we sure do not want to put such constraint on every input, instead, we only want to restrict the access to the security relevant inputs. The goal of this paper is to investigate how to identify which inputs are relevant to system's security.
We have formulated the problem as an security relevancy problem, and deploy static analysis technique to identify security relevant inputs. Our approach are based on dependency analysis technique, it identifies if the behavior of any security critical action depends on certain input. If such a dependency relationship exists, we say that the input is security relevant, otherwise, we say the input is security non-relevant.
We have applied this technique to a security analysis project initiated by Microsoft Windows NT security group. The project is intended to identify security relevant registry keys (a special kind of input) in Windows NT operating system. The results produced from this approach is proved to be useful to enhance Windows NT security. We will report our experience and results from this project in the paper.

Thwarting Denial of Service Attacks against Communication Protocols with Backward Compatible Changes: A Case Study(for Mahesh Tripunitara)
We will discuss a novel approach to building safeguards against denial of service attacks against communication protocols. Our approach involves changes to the relevant communication protocol subject to the following constraint: the protocol that results from the change must be backward compatible with the unchanged protocol. That is, an entity that employs the changed protocol must be able to communicate with an entity that employs the unchanged version.
We will look at a specific problem in this context. The problem involves a class of denial of service attacks against IP. The class is called ARP (Address Resolution Protocol) cache poisoning and involves an attacker introducing a spurious IP to Ethernet mapping in a victim's ARP cache. We will discuss the solution and some implementation aspects of it. Apart from being backward compatible, our solution has two favourable properties: it is implemented as middleware, and is asynchronous