We present a taxonomy and an algebra for attack patterns on component-based operating systems. In a multilevel security scenario, where isolation of partitions containing data at different security classifications is the primary security goal and security breaches are mainly defined as undesired disclosure or modification of classified data, strict control of information flows is the ultimate goal. In order to prevent undesired information flows, we provide a classification of information flow types in a component-based operating system and, by this, possible patterns to attack the system. The systematic consideration of informations flows reveals a specific type of operating system covert channel, the covert physical channel, which connects two former isolated partitions by emitting physical signals into the computer's environment and receiving them at another interface.
Lampson @cite_16 made a basic distinction between legitimate channels, storage channels and covert channels in operating systems, which is considerably extended in our work.
@cite_16
2099137371
Wireless covert channels promise to exfiltrate information with high bandwidth by circumventing traditional access control mechanisms. Ideally, they are only accessible by the intended recipient and---for regular system users operators---indistinguishable from normal operation. While a number of theoretical and simulation studies exist in literature, the practical aspects of WiFi covert channels are not well understood. Yet, it is particularly the practical design and implementation aspect of wireless systems that provides attackers with the latitude to establish covert channels: the ability to operate under adverse conditions and to tolerate a high amount of signal variations. Moreover, covert physical receivers do not have to be addressed within wireless frames, but can simply eavesdrop on the transmission. In this work, we analyze the possibilities to establish covert channels in WiFi systems with emphasis on exploiting physical layer characteristics. We discuss design alternatives for selected covert channel approaches and study their feasibility in practice. By means of an extensive performance analysis, we compare the covert channel bandwidth. We further evaluate the possibility of revealing the introduced covert channels based on different detection capabilities.