Specognitor: Identifying Spectre Vulnerabilities via Prediction-Aware Symbolic Execution

Spectre attacks exploit speculative execution to leak sensitive information. In the last few years, a number of static side-channel detectors have been proposed to detect cache leakage in the presence of speculative execution. However, these techniques either ignore branch prediction mechanism, detect static pre-defined patterns which is not suitable for detecting new patterns, or lead to false negatives. In this paper, we illustrate the weakness of prediction-agnostic state-of-the-art approaches. We propose Specognitor, a novel prediction-aware symbolic execution engine to soundly explore program paths and detect subtle spectre variant 1 and variant 2 vulnerabilities. We propose a dynamic pattern detection mechanism to account for both existing and future vulnerabilities. Our experimental results show the effectiveness and efficiency of Specognitor in analyzing real-world cryptographic programs w.r.t. different processor families

Prevalence of Bed Bug Infestation (Cimex lectularius) in Prisons in Mazandaran Province, 2015-2017

Background and purpose: Bed bugs (Cimex lectularius) are major human ectoparasites. Before planning and implementation of any control measures against bed bugs in prisons, it is essential to determine the infestation rate. Materials and methods: This descriptive cross-sectional study was performed to determine the prevalence of bed bug infestation in prisons in Mazandaran Province, 2015-2017. A standard checklist was prepared based on the health log of the prisons and was used to collect information on prevalence of bed bugs. Data were analyzed using SPSS V20. Results: The highest rate of infestation (68%) was observed in general ward and the lowest was seen in women's ward (1.23%). Highest infestations were reported at nights (88%) and the highest numbers of bed bugs were collected in metal beds (31%). During three years, there were no reports of bed bugs and their bites in prison 6. The average prevalence was constant in prison 1, while it was descending in prisons 2, 3, 5, and 9 and ascending in prisons 4 and 8. Conclusion: High prevalence of bed bugs in most of the prisons in Mazandaran province could probably be due to their entry into the prisons, re-infestation, and also difficulties in their control. Therefore, continuous monitoring of infestation, monitoring and prevention of bed bugs gaining entry into prisons, revising control measures with collaboration between experts from the Ministry of Health and prison health services are essential to plan for successful bed bug control interventions