• Title/Summary/Keyword: overflow prevention

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A Study of Buffer Overflow Prevention Technique for Secure System (안전한 시스템을 위한 Buffer Overflow 대응기법분석에 관한 연구)

  • 조진호;황현욱;박종백
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.10a
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    • pp.608-610
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    • 2000
  • Buffer Overflow는 가장 핵심적인 해킹기법중의 하나이다. 현재 해킹피해의 대부분을 차지하며 local attack뿐 아니라 remote attack까지 가능하므로 이를 이해함은 보안을 이해하는 차원에서 매우 중요하다. 본 논문에서는 Buffer Overflow의 원리와 최근 발생한 시스템의 해킹 형태를 살펴보고, 이를 방지할 수 있는 기법들을 분석하여 Buffer Overflow에 대응할 수 있는 모습을 그려보고자 한다.

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Development of Wave Overtopping-Overflow Transition Model Based on Full-scale Experiments

  • Mase, Hajime;Kim, Sooyoul;Hasegawa, Makoto;Jeong, Jae-Hoon;Yoon, Jong-Sung
    • Journal of Ocean Engineering and Technology
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    • v.34 no.2
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    • pp.128-135
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    • 2020
  • When high waves and storm surge strike simultaneously, the characteristics of the fluid field change drastically from overtopping according to the wave runup height to overflow through a transition state that combines overtopping and overflows. However, an estimation model or evaluation method has not yet been established because there is not enough engineering data. This study developed a wave overtopping-overflow transition model based on a full-scale experiment involving wave overtopping and overflow transition, which appropriately reproduced the effect of waves or the temporal change in inundation flow. Using this model to perform a calculation for the wave overtopping and overflow transition process under typical circumstances, this study determined the wave runup height and features of the inundation flow under time series changes as an example.

Characteristics of Reservoir Behavior According to Establishment Range of Waterproof Mat During Overflow (차수매트 포설 범위에 따른 저수지 월류시 거동 특성)

  • Kim, Young-Ik;Lee, Ik-Sang;Choi, Don-Hwan;Im, Eun-Sang;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.52 no.2
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    • pp.59-66
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    • 2010
  • This study was performed to develop the embankment protection method that can reduce demage by prevention of embankment loss and collapse from overflow due to heavy rain and flood. For overflow test, model dam was prepared and embankment behaviors were monitored with the established piezometer and strain meter during overflow. As a result of overflow test for model dam, in case of embankment without waterproof mat, the lower end of embankment was collapsed within 40 seconds after beginning of overflow. On the other hand, in case of embankment with waterproof mat, embankment collapse didn't occurred during overflow. Accordingly, establishment of waterproof mat for embankment showed that be absolutely effective for the embankment protection during overflow in reservoir. Also, it showed that the minimum establishment range of waterproof mat to prevent embankment collapse in reservoir is from maximum storage level to the lower end of embankment.

Development of the Pot lid Preventing Overflow (국물 넘침 방지용 냄비 뚜껑 개발)

  • Baek, Seung-Hwa;Cha, Kyung-Ok;Kim, Hyung-Yeon;Kim, Joong-Man
    • Culinary science and hospitality research
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    • v.13 no.1 s.32
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    • pp.204-211
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    • 2007
  • In order to develop a pot lid that would not overflow, three parts were created, each different in size. One cover (A") had a small hole (dia. 10 cm) for the vapor to escape (dia. about 2.5 mm). Another, cover A' had a medium-sized hole (dia. about 5 cm) for the vapor to escape. Cover A (dia. 300 mm, $120\;mm^H$) had a large hole (dia. 100 mm) for the vapor to escape. Because the new cover was partially open while soy paste solution cooking, it showed that it could not only prevent overflow, but also extend the burning approaching and salinity increase time, reducing both cooking time and the amount of energy necessary to cook.

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Buffer Overflow Attack and Defense Techniques

  • Alzahrani, Sabah M.
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.207-212
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    • 2021
  • A buffer overflow attack is carried out to subvert privileged program functions to gain control of the program and thus control the host. Buffer overflow attacks should be prevented by risk managers by eradicating and detecting them before the software is utilized. While calculating the size, correct variables should be chosen by risk managers in situations where fixed-length buffers are being used to avoid placing excess data that leads to the creation of an overflow. Metamorphism can also be used as it is capable of protecting data by attaining a reasonable resistance level [1]. In addition, risk management teams should ensure they access the latest updates for their application server products that support the internet infrastructure and the recent bug reports [2]. Scanners that can detect buffer overflows' flaws in their custom web applications and server products should be used by risk management teams to scan their websites. This paper presents an experiment of buffer overflow vulnerability and attack. The aims to study of a buffer overflow mechanism, types, and countermeasures. In addition, to comprehend the current detection plus prevention approaches that can be executed to prevent future attacks or mitigate the impacts of similar attacks.

Efficient Buffer-Overflow Prevention Technique Using Binary Rewriting (이진 코드 변환을 이용한 효과적인 버퍼 오버플로우 방지기법)

  • Kim Yun-Sam;Cho Eun-Sun
    • The KIPS Transactions:PartC
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    • v.12C no.3 s.99
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    • pp.323-330
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    • 2005
  • Buffer overflow is one of the most prevalent and critical internet security vulnerabilities. Recently, various methods to prevent buffer overflow attacks have been investigated, but they are still difficult to apply to real applications due to their run-time overhead. This paper suggests an efficient rewrite method to prevent buffer-overflow attacks only with lower costs by generating a redundant copy of the return address in stack frame and comparing return address to copied return address. Not to be overwritten by the attack data the new copy will have the lower address number than local buffers have. In addition, for a safer execution environment, every vulnerable function call is transformed during the rewriting procedure.

A Study on the Development of Overflow Cutoff Valve for Liquefied Petroleum Gas Cylinders (액화석유가스 용기용 과류차단밸브의 개발에 관한 연구)

  • Rhim Jong-Kuk
    • Journal of the Korean Society of Safety
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    • v.20 no.2 s.70
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    • pp.158-161
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    • 2005
  • This research is about overflow cutoff valve for liquefied petroleum gas cylinders. This valve was developed based on Bernoulli's equation and Newton's equation. The structure of overflow cutoff valve was made by insert module instead of the ordinary valve that is used at present. Recently, the increase in use of gas for fuel in houses has resulted to more frequent occurrences of gas related accidents. In Korea, the government has made a law for the obligatory use of the cutoff valves. This cutoff valve is not ya developed. This research focuses on the use of over flow cutoff valve for LPG cylinders. If this valve is adapted, many accidents can be prevented.

A Study on the Estimation of Discharge Coefficients with Variations of Side Weir Angle (횡월류 위어 유입각 변화에 따른 유량계수 추정 기초 연구)

  • Wan-Seop Pi;Hyung-Joon Chang;Kye-Won Jun
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.81-89
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    • 2023
  • Recently, due to global warming and urbanization due to the influence of abnormal weather, weather changes are increasing worldwide. Various measures have been proposed to reduce flood damage as flood volume increases due to problems such as an increase in impermeable area due to urbanization and reckless development. In this study, flow characteristics and overflow volume were analyzed using FLOW-3D, a three-dimensional CFD model, in accordance with changes in the cross-flow weir inlet angle installed in the meandering river section, and a basic study was conducted to evaluate the overflow capacity and calculate the flow coefficient. As a result of the analysis, the smaller the inflow angle of the transverse overflow, the lower the water level and flow rate of the main water flow after passing the transverse overflow, and the higher the inflow angle, the higher the water level and the flow rate. In addition, it was confirmed that the direct downstream flow rate decreased compared to the upstream flow rate when the inflow angle of the transverse overflow was 40° or higher.

Prevention of Buffer Overflow in the Mobility Support Router for I-TCP (I-TCP를 위한 이동성 지원 라우터에서의 버퍼 오버플로우 방지)

  • 김창호;최학준;장주욱
    • Journal of KIISE:Information Networking
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    • v.31 no.1
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    • pp.20-26
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    • 2004
  • A congestion control algorithm to prevent buffer overflow in MSR(Mobility Support Router) for I-TCP is proposed. Due to high bit error rate and frequent hand-offs over wireless environment, the current congestion control scheme in TCP Reno over mixed(wired and wireless) network exhibits lower throughput than the throughput achieved over wired only network. I-TCP has been proposed to address this by splitting a TCP connection into two TCP connections over wired section and wireless section, respectively. However, buffer overflow in MSR may occur whenever there are excessive bit errors or frequent hand-offs. This may lead to the loss of packets acked by MSR(resident in buffer) to the sender, but not received by the receiver, breaking TCP end-to-end semantics. In this Paper, a new scheme is proposed to prevent the MSR buffer from overflow by introducing “flow control” between the sender and the MSR. Advertised window for the TCP connection between the sender and the MSR is tied to the remaining MSR buffer space, controlling the flow of packets to the MSR buffer before overflow occurs.