• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.807-819
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• 2019

Greybox fuzzing is known as an effective method to discover unknown security flaws reside in software and has been actively researched today. However, most of greybox fuzzing tools require an executable file. Because of this, a library, which cannot be executed by itself requires an additional executable file for greybox fuzzing. Generating such an executable file is challengeable because it requires both understanding of the library and fuzzing. In this research, we suggest the approach to generate an executable file automatically for a library and implement this approach as a tool based on the LLVM framework. This tool shows that executable files and seed files can be generated automatically by static/dynamic analysis of a unit test in the target project. A generated executable file is compatible with various greybox fuzzers like AFL because it has a common interface for greybox fuzzers. We show the performance of this tool as code coverage and discovered unknown security bugs using generated executable files and seed files from open source projects through this tool.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.2
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• pp.231-242
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• 2013

Recently, automated software testing methods such as fuzzing have been researched to find software vulnerabilities. The purpose of fuzzing is to disclose software vulnerabilities by providing a software with malformed data. In order to increase the probability of vulnerability discovery by fuzzing, we must solve the test suite reduction problem because the probability depends on the test case quality. In this paper, we propose a new method to solve the test suite reduction problem which is suitable for the long test case such as file. First, we suggested the length of test case as a measure in addition to old measures such as coverage and redundancy. Next we designed a test suite reduction algorithm using the new measure. In the experimental results, the proposed algorithm showed better performance in the size and length reduction ratio of the test suite than previous studies. Finally, results from an empirical study suggested the viability of our proposed measure and algorithm for file fuzzing.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.541-548
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• 2017

The smartphone operates the media server daemon to handle audio service requests. Media server daemons, running with a high privilege in the background, caused many vulnerabilities to applications most frequently used in smart devices including smartphones. Fuzzing is a popularly used methodology to find software vulnerabilities. Unfortunately, fuzzing itself is not much effective in such format-strict environments as media services. In this paper, we propose a file format-aware fuzzing in order to efficiently detect vulnerabilities of media server daemon. We acquired a remote arbitrary code execution vulnerability on iOS/tvOS/MacOS/watchOS, and we verified the effectiveness by comparing our methodology with the fuzzers FileFuzz and ZZUF.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.2
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• pp.327-333
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• 2014

The rapid expansion of the software industry has brought a serious security threat and vulnerability. Many softwares are constantly attacked by exploit codes using security vulnerabilities. Smart fuzzing is automated method to find software vulnerabilities. However, Many resources are consumed in fuzzing, because the fuzzing needs to create data model for target software and to analyze a data file and software binary. Therefore, The automated method for efficient smart fuzzing is needed to develop the automated data model. In this paper, through analysing the input file format and optimizing the data structure, we propose an efficient data modeling framework for smart fuzzing and implement the framework for detect software vulnerabilities.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.5
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• pp.119-126
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• 2019

Typical software developed and used by North Korea is Red Star and internal application software. However, most of the existing research on the North Korean software is the software installation method and general execution screen analysis. One of the ways to identify software vulnerabilities is file fuzzing, which is a typical method for identifying security vulnerabilities. In this paper, we use file fuzzing to analyze the security vulnerability of the software used in North Korea's Seogwang Document Processing System. At this time, we propose the analysis of open document text (ODT) file produced by Seogwang Document Processing System, extraction of node based on Document Object Mode (DOM) to determine test target, and generation of mutation file through insertion and substitution, this increases the number of crash detections at the same testing time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.2
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• pp.417-437
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• 2022

The quality of the fuzzing seed file is one of the important factors to discover vulnerabilities faster. Although the prior seed generation paradigm, using dynamic taint analysis and symbolic execution techniques, enhanced fuzzing efficiency, the yare not extensively applied owing to their high complexity and need for expertise. This study proposed the DDRFuzz system, which creates seed files based on sequence-to-sequence models. We evaluated DDRFuzz on five open-source applications that used multimedia input files. Following experimental results, DDRFuzz showed the best performance compared with the state-of-the-art studies in terms of fuzzing efficiency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.31-37
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• 2015

As the forms of cyberattacks become diverse, there has been reported another case of exploiting vulnerabilities revealed while processing either a document or multimedia file that was distributed for attacking purpose, which would replace the traditional method of distributing malwares directly. The attack is based upon the observation that the softwares such as document editer or multimedia player may reveal inherent vulnerabilities on some specific inputs. The fuzzing methods that provide invalid random inputs for test purpose could discover such exploits. This paper suggests a new fuzzing method on document applications that could work in mobile environments, in order to resolve the drawback that the existing methods run only in PC environments. Our methods could effectively discover the exploits of mobile applications, and thus could be utilized as a means of dealing with APT attacks in mobile environments.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.29-32
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• 2017

보안 취약점을 악용하여 소프트웨어를 무력화하는 사이버 공격이 증가함에 따라, 조기에 소프트웨어의 취약점을 발견하고 분석하는 보안 테스팅에 대한 중요성이 높아지고 있다. 보안 테스팅의 자동화된 방법 중 하나인 퍼징 기법은 소프트웨어의 입력에 타당하지 않은 무작위 값을 삽입하여 해당 소프트웨어의 예외 즉, 잠재적인 취약점을 발견할 수 있다. 본 논문은 파일 퍼징 과정에서 효율적인 파일 변이 방법을 제안하고 이를 활용한 퍼징 기법을 통해 소프트웨어의 보안성을 높이고자 한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.3-10
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• 2007

In this paper, we proposed the methodology for security testing using block-based file fault injection. When fault is inserted into software, we consider the format of file in order to efficiently reduce the error that is caused by mismatch of format of file. The Vulnerability the methodology focuses on is related to memory processing, such as buffer overflow, null pointer reference and so on. We implemented the automatic tool to apply the methodology to image file format and named the tool ImageDigger. We executed fault-injection focused on WMF and EMF file format using ImageDigger, and found 10 DOS(Denial of Service) in Windows Platform. This methodology can apply to block-based file format such as MS Office file.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.324-327
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• 2019

소프트웨어의 비정상적인 작동인 크래시는 보안 취약점의 원인이 된다. 이러한 크래시로부터 야기되는 취약점을 예방하기 위해 다양한 테스트케이스를 생성하고 크래시를 발견 및 분석하는 연구가 지속되고 있다. 본 논문에서는 북한 소프트웨어 서광사무처리체계에서 사용하는 국제 사무용 전자문서 형식인 Open Document Format for Office Application (ODF)의 워드프로세스 문서 형태인 ODT파일의 효과적인 보안 테스트케이스를 찾기 위해 먼저 테스트케이스를 도출한다. 도출된 테스트케이스를 데이터 전처리한 후 Feature Selection 기법을 적용하여 의미 있는 속성들을 분류한다. 마지막으로 ODT 파일 내에 크래시를 유발하는 유의미한 속성들을 확인하고 퍼징 테스트케이스 작성 시 메트릭으로 활용할 수 있다.