Research On Secure Sandbox Of Android Application Layer

Android has been developing rapidly since its inception.Nowadays,it is the primary system for most mobile devices,with a huge market share.At the same time,the Android system has attracted more malicious attackers' attention.Attacks from Android system vulnerabilities emerge in an endless stream.The problem of bug fixing on the Android system needs to be addressed.Currently,these repair works can only be achieved through system upgrading by the manufacturers of Android system and mobile phone.However,this method is expensive and the vulnerabilities may not be modified in time.This paper firstly analyzes the Android system vulnerabilities,then propose the Android system vulnerability repairing Strategy Constructing Model(ASVRSCM),which quantifies the vulnerability features of Android system and completes the customization of the vulnerability repair strategy.On this basis,a lightweight security scheme to repair Android system vulnerabilities is designed,and the prototype system of this scheme is implemented,which is named Android Vulnerabilities Protection(AVP).When the risk application runs in the AVP,the AVP monitors the running process of the application,intercepts the attack on the vulnerability of the system and prevents its harm to the user.The main work and achievements of this paper are as follows:(1)We study vulnerabilities and protection technologies on Android.For detailed,we focused on Ret2libc,ROP,heap Spray,Ret2dir,and GOT table overwrite attack techniques.In addition,we have studied five protective technologies,including ASLR,DEX/XN,Sandbox,calibration mechanism,and Trust Zone.(2)We analyze vulnerabilities in Android system and propose a strategy establishment model to repair Android vulnerability,which consists of two modules:vulnerability feature quantifiable module and vulnerability repair strategy building module.The former is responsible for quantitative analysis of Android vulnerabilities and the later is responsible for building a vulnerability repair strategy from a number of dimensions based on the results of quantitative analysis.(3)Using a constructed Android vulnerability repair model,we designed the prototype system,AVP,which consists of two parts,the server and the client.The server is made up of the Policy Saving Points(PSPs),which is responsible for the storage of the security strategy.As main part of AVP,the client,composed of three parts,Android App,Policy Enforcing Point(PEP)and Policy Decision Point(PDP),is responsible for the execution of security policy.(4)We conduct security test and performance test of the AVP.The test results show that the proposed method is effective in protecting the Android system while having good performance and compatibility.