Cloud systems are now highly pervasive and provide significant opportunities for adversaries to attack these systems. Therefore, there is a need to understand how attacks can be performed in a Cloud environment. It is important to perform this analysis for historical attacks — to analyse what happened and what alternate routes an adversary could have taken to reach their goals. However, it is also important to have a capability to perform speculative analysis in terms of what potential attacks could have been performed considering a specific set of vulnerabilities. Therefore, this work investigated modelling the dynamic cloud environment, threats to it and how an adversary could reach specific goals.
This work proposes to use a Petri net to model the environment. Petri nets were chosen as they provide convenient ways to model and analyse distributed systems. Using Petri net models of different threats, speculative analysis can be performed to identify different goals that an adversary could reach.
Understanding what goals and adversary could reach and how is an important aspect of knowing where to deploy mitigations. For example, this analysis could assist in applying the Cyber Kill Chain methodology by better understanding where applying mitigations is most effective.
Vulnerability databases (such as CVE) are very useful in the way in which they document vulnerabilities. However, as these vulnerabilities lack a technical specification, it means that to use a vulnerability in this analysis it impact needs to be manually specified. Future work in this area could consider formal specification of vulnerabilities (either in terms of the vulnerability or its impact) as part of their reporting.