Success Rate of Remote Code Execution Attacks : Expert Assessments and Observations

This paper describes a study on how cyber security experts assess the importance of three variables related to the probability of successful remote code execution attacks: (i) non-executable memory, (ii) access and (iii) exploits for High or Medium vulnerabilities as defined by the Common Vulnerability Scoring System. The rest of the relevant variables were fixed by the environment of a cyber defense exercise where the respondents participated. The questionnaire was fully completed by fifteen experts. These experts perceived access as the most important variable and availability of exploits for High vulnerabilities as more important than Medium vulnerabilities. Non-executable memory was not seen as significant. Estimates by the experts are compared to observations of actual attacks carried out during the cyber defense exercise. These comparisons show that experts' in general provide fairly inaccurate advice on an abstraction level such as in the present study. However, results also show a prediction model constructed through expert judgment likely is of better quality if the experts' estimates are weighted according to their expertise.QC 20120702</p

Finding and Exploiting Vulnerabilities in Embedded TCP/IP Stacks

In the context of the rapid development of IoT technology, cyber-attacks are becoming more frequent, and the damage caused by cyber-attacks is remaining obstinately high. How to take the initiative in the rivalry with attackers is a major problem in today's era of the Internet. Vulnerability research is of great importance in this contest, especially the study of vulnerability detection and exploitation methodologies. The objective of the thesis is to examine vulnerabilities in DNS client implementations of embedded TCP/IP stacks, specifically in terms of vulnerability detection and vulnerability exploitation research. In the thesis, a detection method is developed for some anti-patterns in DNS client implementations using a static analysis platform. We tested it against 10 embedded TCP/IP stacks, the result shows that the developed detection method has high precision for detecting the vulnerabilities found by the Forescout research labs with a total of 88% accuracy. For different anti-patterns, the method has different detection precision and it is closely related to the implementation of the detection queries. The thesis also conducted vulnerability exploitation research for a heap overflow vulnerability that exists in a DNS client implementation of a popular TCP/IP stack. A proof-of-concept of this exploitation is developed. Though there are many constraints for successful exploitations, the ability to conduct remote code execution attacks still makes exploitation of heap overflow vulnerability dangerous. In addition, attacks against TCP/IP stacks can take advantage of the stacks and make it possible for an attacker to exploit vulnerabilities in other devices. Often it takes a huge amount of time for researchers to have deep knowledge of a codebase and to find vulnerabilities in it. But with the developed detection method, we can automate the process of locating vulnerable code patterns to add support for detecting relevant vulnerabilities. Research on the exploitation of vulnerabilities can allow us to discover the potential impact of a vulnerability from the perspective of an attacker and implement targeted defences