Design And Implementation Of Automated Fuzzy Test Tool For Android System Services

Due to its high market share and open source,the security risk of Android devices is much higher than that of other operating system devices.Google has received hundreds of reports related to Android system services in the public vulnerability report,and most of these vulnerabilities exist in local system services mainly written in C++.The existing fuzzy test tools BinderCracker and Fans can cover the testing of native system service interface,but their interface model extraction has the problems of incomplete coverage interface and low efficiency of fuzzy test execution.To solve the above problems,this thesis proposes an interface model extraction scheme based on Android native system services client,and designs and implements an automated fuzzy test tool based on Android native system services.The main research results are as follows:1.Aiming at the problem that the interface model extraction in the previous research does not cover the interface completely,an interface model extraction scheme based on Android native system services is designed and implemented.The scheme proposes an accurate and effective interface discovery strategy and an extraction strategy based on the client interface.The experimental verification on Android 9 shows that the interface discovery strategy of this scheme has higher accuracy than Fans.133 interfaces are extracted from the client interface,which proves the feasibility of the client interface extraction scheme,and finds the inconsistency vulnerability between marshall and unmarshall interfaces that Fans cannot detect.2.Based on the interface model extraction scheme,an automated fuzzy test scheme based on Android native system services is designed and implemented.The scheme designs effective seed parameter generation strategy,fuzzy test execution strategy based on coverage guidance and automatic test strategy.Based on the design scheme,the automated fuzzy test system based on Android native system services is realized,and the automated fuzzy test is carried out on Android 9.Four unique vulnerabilities were found jfrom many vulnerability information,including three denial of service vulnerabilities and one high-risk vulnerability of information disclosure,and the vulnerability was assigned CVE number(CVE-2021-0480)by Google,affecting Android 8 1～11.0。...