Prevent Buffer Overflow Research Articles

BoundWarden: Thread-enforced spatial memory safety through compile-time transformations

This paper presents BoundWarden, a novel spatial memory safety enforcement approach that utilizes a combination of compile-time transformation and runtime concurrent monitoring techniques. The compiler extension component of BoundWarden transparently instruments source code of C programs with the code that allows the runtime component of BoundWarden to comprehensively detect and prevent buffer overflow and other out-of-bound errors in buffers on the stack, heap, as well as BSS and data segments of memory. To reduce runtime overhead of bound checking, the runtime component of BoundWarden leverages the ubiquity of multi-core processors by offloading most of the work to a dedicated bound checking thread, which is responsible for performing bound checking and managing metadata. To preserve memory layout and maintain compatibility with existing libraries and binaries, BoundWarden stores the base and the bound of buffers in a separated dedicated bound table. Experiments showed that the prototype of BoundWarden is effective at enforcing spatial memory safety by successfully passing all 850 tests of RIPE test suite, and 94% of NIST's SARD test suite 89, while the results from the Olden benchmark suite showed that on average BoundWarden introduced roughly 1.85x overhead, compared to the uninstrumented code. • We propose BoundWarden, a spatial memory safety enforcement system. • BoundWarden utilizes compile-time transformation and concurrent monitoring techniques. • BoundWarden enforces spatial memory safety in buffers on stack, heap, BSS, and data segments. • BoundWarden offloads runtime overhead to the bound checking thread. • We evaluate BoundWarden using two test suites and one benchmark.

A Review of Memory Errors Exploitation in x86-64

Memory errors are still a serious threat affecting millions of devices worldwide. Recently, bounty programs have reached a new record, paying up to USD 2.5 million for one single vulnerability in Android and up to USD 2 million for Apple’s operating system. In almost all cases, it is common to exploit memory errors in one or more stages to fully compromise those devices. In this paper, we review and discuss the importance of memory error vulnerabilities, and more specifically stack buffer overflows to provide a full view of how memory errors are exploited. We identify the root causes that make those attacks possible on modern x86-64 architecture in the presence of modern protection techniques. We have analyzed how unsafe library functions are prone to buffer overflows, revealing that although there are secure versions of those functions, they are not actually preventing buffer overflows from happening. Using secure functions does not result in software free from vulnerabilities and it requires developers to be security-aware. To overcome this problem, we discuss the three main security protection techniques present in all modern operating system; the non-eXecutable bit (NX), the Stack Smashing Protector (SSP) and the Address Space Layout Randomization (ASLR). After discussing their effectiveness, we conclude that although they provide a strong level of protection against classical exploitation techniques, modern attacks can bypass them.

FJND-based fuzzy rate control of scalable video for streaming applications

A fuzzy rate controller with buffer constraint in combination with a perceptual quality controller is proposed for streaming applications of the AVC/H.264 scalable (SVC) video. The bit rate of each video layer is controlled separately by the fuzzy controller that adjusts the quantization parameter (QP) on a group of pictures (GOP) basis. The QPs of pictures are computed from the GOP QP by the well-known QP cascading technique. While the fuzzy controller provides the buffering constraint for each video layer, the quality controller tries to improve the perceptual quality of the compressed video based on the foveated just-noticeable distortion (FJND) model. The quality controller regulates the QP of each macroblock around the picture QP based on the visibility threshold of the FJND model. In these applications, the initial buffering allows slight variations of the bit rate leading to produce a variable bit rate (VBR) video bit stream with consistent quality. Experimental results show that the proposed algorithm effectively adapts to the buffer size, while strictly prevents buffer overflow and underflow. In addition, incorporating the perceptual quality controller into the fuzzy rate controller achieves higher perceptual quality at the same bit rate.

A Bandwidth-Aware Video Segments Request Strategy to Optimize User’s QoE in Connected Vehicle Networks

In ITS environment, the driver-assistant services usually demand delivering video content to vehicular users, which is very useful in the intervention of emergency services, and reminds the drivers the traffic jam in ahead road. Nowadays for online video delivery in connected vehicle networks, HTTP adaptive streaming (HAS) is one of the most promising technologies, where a video is encoded into multiple bitrates and then split into small segments. It is crux for ITS service providers how to improve users' QoE through an adaptive video segments request strategy. From the perspective of adaptive matching among segment bitrate, network bandwidth, and buffer occupancy, we propose a bandwidth-aware video segment request strategy to optimize user's QoE (for short Bw-QoE), which consists of two parts, i.e., available bandwidth estimation, and segment's bitrate selection. First, based on the severity of bandwidth fluctuation, Bw-QoE estimates the available bandwidth with different historical weighted average methods. Then constrained by the estimated available bandwidth and buffer occupancy, the adaptive bitrate selection is formulated as an optimization model to maximize user's QoE of a video streaming session. It is fairly attractive for Bw-QoE to prevent buffer overflow, underflow and unuseful download, and to reduce bitrate switching. Compared with the classic strategy (e.g., LIU's strategy), the simulation results show that the proposed strategy Bw-QoE has higher average video bitrate (about 8%-10%), less interruption (about 100%), less segment bitrate switching (about 15%-17%) and higher buffer occupancy (about 13%-51%), which demonstrate that our strategy effectively improves QoE.

Adaptive protocol for full‐duplex two‐way systems with the buffer‐aided relaying

In this study, the authors explore two-way relaying having a full-duplex decode-and-forward relay with two finite buffers. Chiefly, they propose a novel adaptive protocol (that maximises the cumulative network throughput) based on the combination of the buffer states, lossy link, and the outage probability; a decision is generated as to whether it can transmit, receive or even simultaneously receive and transmit information. Towards this objective, first, based on the queue state transition and the outage probability, an analytic Markov chain model is proposed to analyse this scheme, and the throughput and queueing delay are derived. Second, they evaluate the performance of the throughput according to the variation of the self-interference. The authors' numerical results reveal exciting insights. First, the adaptive protocol is optimal when the length of the buffer is superior to a certain threshold. Second, they demonstrate that the adaptive protocol can boost the transmission efficiency and prevent buffer overflow.

Adaptive Resource Observation for Congestion Alleviation using Constrained Application Protocol

This paper presents an adaptive resource observation (ARO) for congestion alleviation using constrained application protocol (CoAP), which prevents buffer overflow of the client by adjusting observing period of the associated servers. The operation of ARO consists of two main phases; 1) buffer overflow estimation, 2) observing period adaptation. In the former, the client estimates whether buffer overflow will occur by comparing its service rate with packet arrival rate, then it determines the new observing period that can prevent buffer overflow of the client. The latter is used to adjust the observing period of servers considering the predefined the minimum and maximum queue threshold. ARO can significantly reduce the number of dropped packets caused by buffer overflow. The simulation results show that ARO achieves a higher network performance than legacy CoAP.

Fuzzy logic-based scalable video rate control algorithm for high-delay applications of scalable high-efficiency video coding

The second version of the high-efficiency video coding standard introduced a scalable extension, which is called scalable high-efficiency video coding. It is necessary to design appropriate rate controllers for this extension based on the specific application requirements. According to delay and buffering constraints, rate control algorithms are divided into constant bit rate and variable bit rate (VBR) algorithms. Our focus is on high-delay applications like streaming and broadcast for which VBR controllers are suitable. Our proposed VBR controller utilizes a fuzzy logic-based algorithm to control long-term average bit rate while preventing buffer overflow or underflow. Targeting perceptual quality, the proposed algorithm has been implemented at the group of pictures level to minimize unnecessary fluctuations of quantization parameter and consequently minimizing video quality fluctuations. Experimental results show a high performance in terms of rate control and quality of the compressed video for the proposed algorithm.

Simulation Study of Dynamic Observing Period Adjustment for CoAP-based Monitoring Systems

Objectives: This paper is a simulation study of dynamic observing period adjustment (DOPA) to determine the appropriate DOPA stage value that prevents the buffer overflow in various constrained application protocol (CoAP) based monitoring systems. Methods/Statistical Analysis: To determine the appropriate DOPA stage value for various CoAP-based monitoring systems, we set a variety of simulation scenarios that use different values of simulation parameters and investigate the number of successful transmissions and dropped messages of each simulation. Then, we determine the appropriate DOPA stage value of each scenario, which prevents buffer overflow and maximizes the number of successful transmissions simultaneously. Findings: The experimental simulation is conducted under various simulation scenarios. The simulation results show that the appropriate DOPA stage value increases as the number of devices or payload size increases. It also increases when the observing period of servers or clock rate decreases. The correlations between the DOPA stage value and simulation parameters are obtained through these results, which is used for determining the appropriate DOPA stage value. Improvements/Applications: Our study can be used to provide an optimal observing period for buffer overflow prevention in various monitoring systems.

Markov Modeling for Practical Two-Way Relay With Finite Relay Buffer

Two-way XOR relaying enables the hidden nodes to communicate at high data rates, and the buffer allocation plays a critical role in improving the system performance. This letter investigates the practical two-way relay protocol with an enhanced transmission scheduling, which takes a joint consideration of the finite relay buffer, signalling overhead, and lossy link. Based on the queue state transitions and the link qualities, an analytic Markov chain model is proposed to analyse this scheme, and the closed-form expressions for the throughput and queueing delay are derived. Simulations demonstrate the accuracy of the analytic model, and also show that the enhanced scheme can improve transmission efficiency and prevent buffer overflow. Our analytic model can also be used as an online tool to configure a reasonable buffer resource to achieve a higher throughput under an acceptable delay.

PREVENTING BUFFER OVERFLOW ATTACKS WITH RELIABLE AND LOW COST SYSTEM

Detection of Data Flow Anomalies There are static or dynamic methods to detect data flow anomalies in the software reliability and testing field. Static methods are not suitable in our case due to its slow speed; dynamic methods are not suitable either due to the need for real execution of a program with some inputs. Their scheme is rule-based, whereas SigFree is a generic approach which does not require any pre-known patterns. Then, it uses the found patterns and a data flow analysis technique called program slicing to analyze the packet’s payload to see if the packet really contains code Four rules (or cases) are discussed in this work.

Reliable Packet Flow Control for Preventing Buffer Overflow in Wi-Fi Serial Bus

This letter proposes a novel buffer management scheme for improving the packet delivery of Universal Serial Bus (USB) services in wireless networks. In the future, USB may be used with various wireless services, most notably Wi-Fi, thus realizing Wi-Fi USB (WSB). However, data transmission of Wi-Fi and USB is asynchronous due to differences in their Medium Access Control (MAC), resulting in buffer overflow. To alleviate this problem, we propose an overflow prevention scheme where rates of USB transmission are varied depending on status of Wi-Fi. The proposed scheme is evaluated via the NS-3 simulator, showing that the packet delivery ratio of USB data can reach near 100% even in wireless transmission.

On the design of a new dynamic credit-based end-to-end flow control mechanism for HPC clusters

Adaptation of the credit-based flow-control mechanism to the EXTOLL interconnect.In-depth evaluation of the previous flow control including the use of piggybacking.Design of a lightweight dynamic credit-based flow-control mechanism for clusters.Thorough performance evaluation of the new dynamic flow control.Analysis of the memory footprint of both flow control versions. High Performance Computing usually leverages messaging libraries such as MPI, GASNet, or OpenSHMEM, among others, in order to exchange data among processes in large-scale clusters. Furthermore, these libraries make use of specialized low-level network layers in order to achieve as much performance as possible from hardware interconnects such as InfiniBand or 40Gb Ethernet, for example. EXTOLL is an emerging network targeted at high performance clusters.Specialized low-level network layers require some kind of flow control in order to prevent buffer overflows at the receiver side. In this paper we present a new end-to-end flow control mechanism that is able to dynamically adapt, at execution time, the buffer resources used by a process according to the communication pattern of the parallel application and the varying activity among communicating peers. The tests carried out on a 64-node 1024-core EXTOLL cluster show that our new dynamic flow control mechanism presents very low overhead with an extraordinarily high buffer efficiency, as overall buffer resources are reduced by 4i? with respect to the amount of buffers required by a static flow control protocol achieving similar low overhead levels.

Usage of Variable Structure Congestion Control Protocol (VCP) in Buffer Overflow Attack Blocker

In this paper, we proposed the usage of “Variable Structure Congestion Control Protocol” in network communication to avoid Buffer Overflow thereby preventing Buffer Overflow Attacks. In general transferring a signal between connected Clients are done through “Transmission Control Protocol” in which only two states are clearly shown i.e. either “0” or “1”. For successful transmission “1” is represented and for failure transmission “0” is represented during transmission process. In “Variable Structure Congestion Control Protocol “there are four possible states for representing the signal transmission. They are “00, 01, 10, and 11”. Through VCP the signal transmission can be classified as “Low load region”, “High load region” and “Overload region” from which the transmission load can be monitored thereby preventing “Buffer Overflow” in network transmission. Round Trip Time (RTT) and Round Trip Time Timeout (RTO) have been calculated together with VCP to prevent buffer overflow attack during signal transmissions.

Adaptive load balancing algorithm for multiple homing mobile nodes

In places where mobile users can access multiple wireless networks simultaneously, a multipath scheduling algorithm can benefit the performance of wireless networks and improve the experience of mobile users. However, existing literature shows that it may not be the case, especially for TCP flows. According to early investigations, there are mainly two reasons that result in bad performance of TCP flows in wireless networks. One is the occurrence of out-of-order packets due to different delays in multiple paths. The other is the packet loss which is resulted from the limited bandwidth of wireless networks. To better exploit multipath scheduling for TCP flows, this paper presents a new scheduling algorithm named Adaptive Load Balancing Algorithm (ALBAM) to split traffic across multiple wireless links within the ISP infrastructure. Targeting at solving the two adverse impacts on TCP flows, ALBAM develops two techniques. Firstly, ALBAM takes advantage of the bursty nature of TCP flows and performs scheduling at the flowlet granularity where the packet interval is large enough to compensate for the different path delays. Secondly, ALBAM develops a Packet Number Estimation Algorithm (PNEA) to predict the buffer usage in each path. With PNEA, ALBAM can prevent buffer overflow and schedule the TCP flow to a less congested path before it suffers packet loss. Simulations show that ALBAM can provide better performance to TCP connections than its other counterparts.

A Fuzzy Logic Based Network Congestion Control Using Active Queue Management Techniques

Conventional IP routers are passive devices that accept packets and perform the routing function on any input. Usually the tail-drop (TD) strategy is used where the input which exceeds the buffer capacity are simply dropped. In active queue management (AQM) methods routers manage their buffers by dropping packets selectively. We study one of the AQM methods called as random exponential marking (REM). We propose an intelligent approach to AQM based on fuzzy logic controller (FLC) to drop packets dynamically, keep the buffer size around desired level and also prevent buffer overflow. Our proposed approach is based on REM algorithm, which drops the packets by drop probability function. In our proposal we replace the drop probability function by a FLC to drop the packets, stabilize the buffer around the desired size and reduce delay. Simulation results show a better regulation of the buffer. Keywords: Random exponential marking; Active queue management; Fuzzy logic controller; Pro-active queue management. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.2786 J. Sci. Res. 2 (2), 273-284 (2010)

A Dynamic Performance-Based Flow Control Method for High-Speed Data Transfer

New types of specialized network applications are being created that need to be able to transmit large amounts of data across dedicated network links. TCP fails to be a suitable method of bulk data transfer in many of these applications, giving rise to new classes of protocols designed to circumvent TCP's shortcomings. It is typical in these high-performance applications, however, that the system hardware is simply incapable of saturating the bandwidths supported by the network infrastructure. When the bottleneck for data transfer occurs in the system itself and not in the network, it is critical that the protocol scales gracefully to prevent buffer overflow and packet loss. It is therefore necessary to build a high-speed protocol adaptive to the performance of each system by including a dynamic performance-based flow control. This paper develops such a protocol, performance adaptive UDP (henceforth PA-UDP), which aims to dynamically and autonomously maximize performance under different systems. A mathematical model and related algorithms are proposed to describe the theoretical basis behind effective buffer and CPU management. A novel delay-based rate-throttling model is also demonstrated to be very accurate under diverse system latencies. Based on these models, we implemented a prototype under Linux, and the experimental results demonstrate that PA-UDP outperforms other existing high-speed protocols on commodity hardware in terms of throughput, packet loss, and CPU utilization. PA-UDP is efficient not only for high-speed research networks, but also for reliable high-performance bulk data transfer over dedicated local area networks where congestion and fairness are typically not a concern.

Code quality tools

In this paper we share some of our experiences relating to tools used in coding phase. We primarily focus our discussion on two topics, namely UT (Unit Testing) and Memory related errors. Unit Testing (UT) [1] is a critical early-phase verification activity that ensures the quality of the product soon after the code is ready. Newer paradigms of software development like Extreme Programming [7] have a strong focus on UT. However, UT is very effort-intensive as it involves test harness development and repetitive execution. In Motorola software Group, we evaluated a set of commercial tools and selected a tool for use in our projects. In this paper, we will share the evaluation criteria, which was identified for the tool selection and the various technical challenges encountered in adopting a UT tool solution in a heterogeneous environment along with the associated learning. One of the major challenges encountered, was arriving to a consensus on definition of term 'Unit'. The other issues included handling of complex data structures, event driven code, integration with development environment etc. One of the major categories of errors introduced and found in coding phase relates to memory. As these errors may have security implications, leaving them undetected might be a big risk. For trapping memory related errors, a framework to categorize these errors was created along with the associated code samples. In this paper, two types of memory related errors will be discussed, namely memory leak and buffer overflow. This memory related errors can be exploited to compromise the security of the system. This paper also discusses the causes, types and impact of buffer overflows, as well as the precautions to be taken to prevent buffer overflows.

Microarchitectural Protection Against Stack-Based Buffer Overflow Attacks

Although researchers have proposed several software approaches to preventing buffer overflow attacks, adversaries still extensively exploit this vulnerability. A microarchitecture-based, software-transparent mechanism offers protection against stack-based buffer overflow attacks with moderate hardware cost and negligible performance overhead

Queueing network models of credit-based flow control

Credit-based flow control schemes are a commonly used means of preventing buffer overflow in high-speed networks spanning a local area. Fibre Channel, a widely-used storage area networking technology, and InfiniBand, a recently developed system area network technology, are examples of two network technologies that employ credit-based flow control. With credit-based flow control, the receiver sends credits to the sender to indicate the availability of receive buffers; the sender waits for credits before transmitting messages to the receiver. We present two models of credit-based flow control operation. In particular, we consider a fork-join queueing system with two input queues; the message population feeds one queue and the credit population the other. We consider the case of bulk message arrivals and single arrivals drawn from a finite population. Our analysis yields stationary probability distributions for message queue length and number of available credits. We provide equations for mean message queue length, mean number of credits, throughput, and mean message waiting time.

이진 코드 변환을 이용한 효과적인 버퍼 오버플로우 방지기법

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.