(Springer Verlag, 2014) Kharchenko, V.; Abdul-Hadi, A.M.; Boyarchuk, A.; Ponochovnyi, Y. L.
The paper examines the issues of web systems assessment availability. It is defined that unavailability of web services may be caused by internal and external factors in particular server side vulnerability attacks. Three Markov’s models of web system availability are developed; these models consider influence of software defects and vulnerability attacks for DNS, DHCP and Route services. Elimination of configuration vulnerabilities during system operation is considered. Conclusions about the impact of the probability of detection and elimination of vulnerabilities and the recovery rate on the web systems availability function are proposed.