At both intel and microsoft, we jointly recognized the seriousness of control flow subversion attacks and recognized the challenge in developing the means to protect from return oriented. Im certain there is room for improvement and original ideas there. In this paper, we present an approach to attack on the xen hypervisor utilizing returnoriented programming rop. Virtualization security issues and mitigations in cloud. Return oriented programming rop is one more attack mentioned in literature over xen hypervisor which is very successful attack. Xen handles these events appropriately for correct virtualization, and we. The xen project is focused on advancing virtualization in a number of different commercial and open source applications, including server virtualization, infrastructure as a services iaas, desktop virtualization, security applications, embedded and hardware appliances, and automotiveaviation.
Exploit two xen hypervisor vulnerabilities black hat. Attackers must also leverage return oriented programming rop to abuse the victim programs legitimate code in order to prime the processor with the correct data. Returnoriented programming is an effective codereuse attack in which short code sequences ending in a ret instruction are found within existing binaries and. Isolating commodity hosted hypervisors with hyperlock. The method includes initiating a compute signature hardware instruction of a computing device to compute a signature for a return address and the associated location on the stack the return address is stored. Add dmops to allow use of vga with restricted qemu x86. This report, hardware assisted rop detection mode hard mode is presented as a. In a buffer overrun, a function that does not perform proper bounds checking before storing userprovided data. We used xen hypervisor see number 4 in references as a case study to bring out some key aspects related to system architecture that will be applicable for most hypervisor software models and thus help in choosing the right virtualization solution. The hardwareenforced boundary between a hypervisor and its guest grants a hypervisorbased security system independence from the guest os as well as a degree of.
This also makes hardware requirements flexible because as long as xen is supported and domain0 has the needed drivers, a particular virtual os will be able to run on any machine. Attacks against network functions virtualization and software. In this paper, we present an approach to attackon the xen hypervisor utilizing return oriented programming rop. A rop is a type of attack that modifies codes already existing in the hypervisor memory space instead of injecting new codes. Riddle and chang 18 introduce an attack on the xen hypervisor that allows the attacker to escalate their vms to a privileged state. In particular, an attack based on code reuse called return oriented programming rop 5 is now the preferred technique. How does xen work 8 xen hypervisor domain u pv guest pv block driver shared memory data dom u data dom u. It reuses existing binary code instead of injecting its own code and is able to perform arbitrary computation due to its turingcompleteness. Attacks against network functions virtualization and. In this paper, we present an approach to attackon the xen hypervisor utilizing returnoriented programming rop. A method preventing kernel returnoriented programming attack is proposed, which creates a separated secret address space for control data taking advantage of vmm architecture.
Return oriented programming rop attacks, including on. Actually xen lies between paravirtualization and full virtualization. Cs6v81 is a graduate level, research oriented, system and software security course. For example, early studies assumed the hypervisor of a remote host to be. Us9646154b2 return oriented programming rop attack.
Return oriented programming rop attack prevention techniques are described. In this study the authors construct attacks that target hypervisor noncontrol data to demonstrate which types of data within the xen hypervisor are critical to system security. This paper presents various security issues related to hypervisor in cloud. Since xen is a hypervisor, nearly any system running xen would be able to use the os in the. In one or more examples, a method is described of protecting against return oriented programming attacks. Xen integrates its hypervisor on a linux kernal, so that we have to compile and run this modified kernel on the server on which we wish to perform the virtualization. It is the first program running after the bootloader exits. Creditbased scheduling is done in xen hypervisor which uses token bucket. Returnoriented programming attack on the xen hypervisor.
A lightweight approach to provide lifetime hypervisor. It uses existing code for attack virtualization security issues. Unfortunately, contemporary hypervisors such as xen 5 and vmware 52 still have a large, complex code base e. The goal of this course is to explain the lowlevel system details from compiler, linker, loader, to os kernel and computer architectures, examine the weakest link in each system component, explore the left bits and bytes after all these transformations, and study the stateoftheart offenses. These type of attacks are prevalent in memory unsafe languages such as. Return oriented programming rop has recently caught great attention of both academia and industry. In the process of virtualization security research on it, our team. Os virtualization zones, and hardware virtualization of both type 1 xen and type 2 kvm varieties.
Show the practical applications of return oriented programming to exploitation of memory corruption vulnerabilities preventing the introduction of malicious code is not enough to prevent the execution of malicious computations1 demonstrate that while exploit mitigations makedemonstrate that while exploit mitigations make. It presents the domains with a virtualmachine that looks similar but not identical to the native architecture. The figure below shows the previously described situation. Riddle and chang 18 introduce an attack on the xen hypervisor that allows the attacker to escalate their vms to a privileged state by using returnorientedprogramming. Return oriented programming rop is one more attack mentioned in literature 23 over xen hypervisor which is very successful attack. Paravirtualization avoids the need to emulate a full set of hardware and firmware services, which makes a pv system simpler to manage and reduces the attack surface exposed to potentially malicious guests. Osindependent software based full disk encryption secure against main memory attacks, 2012. Chang 18 introduce an attack on the xen hypervisor that allows the attacker to. Review open access a survey on securing the virtual cloud. Recordreplay architecture as a general security framework. Writes to the new mapping will overwrite portions of the stack, introducing a vector to a traditional return tolibc or return oriented programming attack. Generally, these types of attacks arise when an adversary manipulates the call stack by taking advantage of a bug in the program, often a buffer overrun.
This paper also brings issues possible with a malicious virtual machine running over hypervisor such as exploiting more resources than allocated by vm, stealing sensitive data by bypassing isolation of vm through side channel attacks, allowing attacks to compromise hypervisor. A survey on securing the virtual cloud journal of cloud. Xen can run paravirtualized guests pv guests in xen terminology even on cpus without any explicit support for virtualization. In 2017 project zero demonstrated a kernel exploit for. Prevent kernel returnoriented programming attacks using. Bloated tcb of type i hypervisors hypervisor hypervisor sloc tcb xen 4. Return oriented programming rop has recently caught great attention of both. Return oriented programming my masters work was with a buffer overflow exploit technique dubbed return oriented programming on the sparc architecture. It modifies the data in the hypervisor that controls whether a vm is privileged or not and thus can escalate the privilege of an unprivileged domain domu at run time. Return oriented programming rop is a form of codereuse attack employed in many modern exploitation attacks. In this paper, we present hypercrop, a hypervisorbased approach to counter such attacks. The admin vm may export a management tool, with virtual machine introspection.
Architectural support for programming languages and. Use of role based access control for securitypurpose. It modifies the data in the hypervisor that controlswhether a vm is privileged or not and thus can escalatethe privilege of an unprivileged domain domu at runtime. It has been shown that by carefully analyzing the source code and the resultant binary of the xen hypervisor, it is possible to identify vulnerable pieces of code that contain short instruction sequences ending with the cpu ret instruction, which can further be chained together to execute and produce the desired. In this paper, we look into using virtualization technologies to defeat return. We have built a proofofconcept hyperlock prototype to confine the popular kvm hypervisor on linux.
Eliminating the hypervisor attack surface for a more. The secret address space is implemented as a shadow stack on the same host with the target os facilited by hardware virtualization techniques. The hypervisor is responsible for checking page tables, allocating resources for new domains, and scheduling domains. I extended the work done in our original ccs paper to automate the search for a turingcomplete set of gadgets. Hence, it can successfully bypass stateoftheart code integrity mechanisms such as nickle and secvisor. Pdf virtualization security issues and mitigations in cloud. Secure applications on an untrusted operating system. A microhypervisorbased secure virtualization architecture udo steinberg et al, eurosys 10. Us patent for return oriented programming rop attack. The implant then persists for a time sufficient enough to carry out some malicious effect, obtain useful information, or propagate intrusion to other systems. Xen also supports virtual servers management though graphical interfaces. It goes between the hardware and the operating systems of the various domains. Misuse patterns for virtual machine environment of nfv.
Xen hypervisor is the basic abstraction layer of software that sits directly on the hardware below. Pdf virtualization security issues and mitigations in. The xen project hypervisor is an exceptionally lean software layer that runs directly on the hardware and is responsible for managing cpu, memory, and interrupts. Software happenings will be traced by observing behaviour in. We design and implement hypercropii, a virtualization. Return oriented programming ropjump oriented programming jop attack protection jul 5, 2016 apple in an embodiment, a processor includes hardware circuitry andor supports instructions which may be used to detect that a return address or jump address has been modified since it. Xen hypervisor case study white paper designing amit. It shows privilege, resource utilisation and security policy related data are vulnerable to returnoriented programming or dma attacks. Migrating security components to the hypervisor provides security, efficiency, and manageability benefits. The spectre attack requires that the processors speculative execution engine be tricked into incorrectly executing code within victim application. Unlike the time to execute an exploit, the time spent.