As computer security becomes important, various system security mechanisms have been developed. Especially anomaly detection using hidden Markov model has been actively exploited. However, it can only detect abnormal behaviors under predefined threshold, and it cannot identify the type of intrusions. This paper aims to identify the type of intrusions by analyzing the state sequences using Viter...

The size and complexity of software systems is growing, increasing the number of bugs. Many of these bugs constitute security vulnerabilities. Most common of these bugs is the buffer overflow vulnerability. In this paper we implement a testbed of 20 different buffer overflow attacks, and use it to compare four publicly available tools for dynamic intrusion prevention aiming to stop buffer overf...

Buffer overflow attacks are one of the most important attack classes because they enable an attacker to remotely execute arbitrary code at the target host. These attacks generaly disturb the network traffic at the application level by delivering anomalous data to the target applications. This work presents a prototype to detect anomalous network traffic containing executable code at the applica...

As computers have become widely used, software vulnerability is now one of the most serious security threats. In particular, viruses and worms that use buffer overflow vulnerabilities are serious threats to computers. Therefore, techniques to detect the execution of malicious code are required when taking measures to prevent intrusion using such software vulnerabilities. An intrusion detection ...

This paper is concerned with a linked analysis of overflow and roundoff errors in fixed-point digital filter realizations. Upper bounds for the overflow error power are obtained, having considered saturation quantizer characteristics. Also, upper bounds for the overflow probability are given in order to overflow power be lower than roundoff noise power. Finally, computer simulation results supp...

Heap and stack buffer overflows are still among the most common attack vectors in intrusion attempts. In this paper, we ask a simple question that is surprisingly difficult to answer: which bytes contributed to the overflow? By careful observation of all scenarios that may occur in overflows, we identified the information that needs to be tracked to pinpoint the offending bytes. There are many ...

In this paper we evaluate the performance of scene detection techniques, starting from the classic precision/recall approach, moving to the better designed coverage/overflow measures, and finally proposing an improved metric, in order to solve frequently observed cases in which the numeric interpretation is different from the expected results. Numerical evaluation is performed on two recent pro...

The present study demonstrates that S(-)-nornicotine evoked a concentration-dependent increase in dopamine (DA) release from superfused rat striatal slices. The increase in DA release was indicated by an S(-)-nornicotine-induced overflow of endogenous 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatal superfusate and by an S(-)-nornicotine-induced increase in tritium overflow from striatal ...